Simostronomy

Exploring Mars by Scott Hubbard (a book review)

2012-01-31T16:45:00.002-05:00

I looked forward to reading this book after the publisher asked me if I wanted a review copy, and eagerly tore into the package when it arrived last week. As you know, I don't usually read or write much about planets or Solar System exploration, but this seemed like a good story, told by the "Mars Czar", Scott Hubbard himself, and I couldn't wait to read it.

I was wrong.

This book should have been titled Exploring the Boring, Navigating the Administrative Guts of the Bloated Bureaucracy that is NASA. This is not the story of exploring Mars, it is the self congratulatory story of Scott Hubbard navigating the financial, political and cultural obstacles that stood in the way of Hubbard in his mission to bring the Mars Program out of the toilet and into the future.

Based on the jacket cover I expected this to be a fascinating story "filled with outsized egos, under-sized budgets and nail-biting tension". Pffft. Compelling? Not.

Yes, it is a great historical document providing insight into the whole excruciatingly painful process of launching successful missions to the Red Planet, and it needed to be told. It was just boring. If you really want to read it, you can have my copy.

Carnival of Space #234

2012-01-31T08:43:00.001-05:00

This week's Carnival of Space is hosted at the Dear Astronomer Blog. The site is run by Ray Sanders, an astronomer with nearly fifteen years of amateur astronomy experience and an education in astronomy/astrophysics. Currently working to make the transition from “backyard astronomer” to “professional astronomer”, Ray is passionate about observing, research, outreach, answering questions submitted to his site, and writing for sites like Universe Today.

If you've never been to the Carnival of Space before you're missing out. The Carnival is a weekly collection of astronomy and space writing from various blogs around the web. Once you've taken the ride you're sure to come back again and again. So, check out this weeks' Carnival of Space #234.

Rod Stubbings- Aussie Amateur Awesomeness

2012-01-27T23:10:00.002-05:00

Rod Stubbings at home in the observatory

I've known Rod Stubbings since 1999, when I got heavily involved in monitoring cataclysmic variables for outbursts for the AAVSO and VSNET. Rod was by far the most active observer in the southern hemisphere, and he was solely responsible for the detection of dozens of rare and significant outbursts and eruptions of variable stars.

I finally had the pleasure of meeting Rod in 2002, at the AAVSO spring meeting in Hawaii. He is a quiet, unassuming man, with a quick smile and a knowing gaze. He doesn't have to say a lot for you to understand there is a lot going on behind those eyes. I liked him right away, and admired him even more after meeting him. Rod had been invited to that meeting by then Director of the AAVSO, Janet Mattei, because she was going to honor him with the AAVSO Director's Award, one of the highest honors our organization bestows on individuals.

Since then he's been plugging away, observing hundreds of variable stars a week from his observatory in Victoria, Australia. He's been at it for over 18 years now. Today I received a note from my Aussie friend informing me that he has passed a significant milestone in his observing career. A few nights ago he made his 200,000th variable star observation, placing him in the top five visual observers in the history of variable star astronomy.

Hi Mike,

A few nights ago I reached a personal milestone of observing over 200,000 visual observations. This has taken 18 years and 8 months since 1993 which basically means I haven't been anywhere in that time frame! You might be pleased to know that I have finally caught up with my backlog of typing up data and all my observations up to December 2011 are in. I don't want to get 12 months behind ever again. Anyway another clear night tonight so back out to see what I can find until morning.....don't have to work tomorrow!

Cheers,
Rod

I was honored Rod thought enough of me to send a personal message, informing me of this outstanding achievement.
Yes, 200,000 is a big number, but let's examine what that means in terms of commitment-
Let's assume he can do 100 stars per night. I'm sure Rod can do more, but sometimes the weather will stop you short. That means he has spent somewhere in the neighborhood of 2000 nights under the stars in 224 months. That's 9-10 nights every month for 18 years and 8 months.

If it takes Rod 90 seconds apiece, and that alone should give you an idea of the kind of productivity we're talking about- that's a minute and a half to find the variable, estimate its brightness record it and move on to the next one- that comes to about 5000 hours of observing time at the eyepiece.

Of course, you don't just walk outside and begin observing. You have to open the observatory, uncover the telescope, get your bearings, turn on your dew heater, etc., etc. And at the end of the night there is a routine to closing up the dome that may be equally as long, so let's add say 20 minutes to each night he observes. That's an additional 667 hours total.

Observations not reported to anyone are not observations, and Rod's do not sit in a drawer or spin on a hard drive somewhere, useless to science. He has taken the time to report them all to the AAVSO and other groups over the years. Let's assume it takes him about an hour to type up 100 observations. That's another 2000 hours at the keyboard entering data and submitting reports.

Add it all up, and you begin to get a perspective on the kind of commitment we're talking about here. He has devoted approximately 7667 hours of his life in the last 18.75 years to variable stars. Or 409 hours a year at the telescope and keyboard. Roughly 3 hours a night 10 times a month, every month, for longer than I've known him.

Consider this also, Rod has been working full time throughout this period to support his family. This amounts to 896 work weeks. In the same time period he has invested the equivalent of 192 work weeks observing and reporting variable star activity.

Rod Stubbings is the quintessential citizen scientist. He has devoted an incredible amount of his time, money and effort into helping astronomers understand the structure and evolution of compact binary systems and other unusual stars, and he has done it all for the love of it.

He doesn't get paid. He doesn't have a grant to assist in the expenses of his contributions to science. He has received recognition and awards, but that isn't what motivates Rod. He just has his trusty telescope, an intimate knowledge of the night sky and an unwavering passion for variable star science.

So, what's next for a verified madman and variable star junkie? Rod says, "I told my daughter I was going to slow down and re-discover my family. Unbeknown to her it was only for a few weeks. When she found out she cracked up laughing, saying "I should have read the fine print!""

Congratulations, Rod. I hope we get to meet again, before you catch up to the other living legend of variable star observing in the southern hemisphere, Albert Jones. It's rarified air you're breathing down under these days.

Puckett Scores, AAVSO Gets the Assist

2012-01-24T17:46:00.000-05:00

As most of you know, there are astronomers searching the sky every clear night in an attempt to discover new supernovae in distant galaxies. Some individuals, like Berto Monard and Tom Boles, excel at this, having discovered over 100 supernovae each. One of the more successful supernova search teams is the Puckett Observatory Supernova Search Team, with over 250 supernova discoveries.

All these individuals and teams use robotic telescopes, running scripts that point the telescope and take CCD images of galaxies in a long list of targets they try to cover as often as possible. The nightly images are then “blinked” (rapidly switching between two images of the same star field) by team members looking for the telltale sign of a new star in or near the galaxies in the images. When a team member finds a suspected supernova, this is reported to the IAU, and then listed on the CBAT Transient Objects Confirmation Page. If it is a possible SN it gets a temporary designation of PSN (possible supernova) followed by its coordinates (PSN J01560719+1738468). The search team then asks other astronomers to obtain confirmation images and spectra to confirm the discovery and classify the type of the supernova.

Once the discovery is confirmed the IAU names the supernova according to their established convention and makes a formal announcement in a CBAT Electronic Telegram (CBET), an IAU electronically distributed notification system.

Most of the time, the AAVSOnet telescopes only observe supernovae that have been confirmed, are bright at discovery (14th magnitude or brighter), are well situated outside the core of the galaxy (because it makes them easier to measure accurately), and are confirmed Type Ia supernovae, because these are the standard candles professional astronomers are most interested in currently. The AAVSO robotic telescopes are not involved in supernova or nova searches, per se, but in the course of a year we do get several requests to confirm or deny supernovae or novae.

Telescope shelters at Astrokolhoz, the AAVSOnet telescope farm in New Mexico

Recently, Tom Krajci, the AAVSOnet telescope farm operator and technical guru, has been testing the robotic telescope software and hardware to respond to real-time alerts from the Virtual Observatory and other sources.

"It's an obvious need for events like gamma ray bursts, where minutes and seconds count, but even for slower transient events, such as confirming supernovae, it opens doors to new possibilities," said Tom. "I currently run five AAVSONet scopes on my hill. The largest scope has an aperture of fourteen inches, and the smallest (Bright Star Monitor) is 60 millimeters. Now that I'm learning how to customize scripts that filter and respond to VO events, I can tailor the response by choosing the appropriate telescope. And that's only the beginning."

Tom explained some of the advantages of the current software, "AAVSONet scopes use ACP Scheduler software, which not only is capable of responding to VO event messages, but also creating and sending automated messages back to that community - informing them that we have successfully acquired images of a given event. This is not just a good news announcement. It may allow other observers to re-task assets to other targets that have not yet received any follow up observations. Automation can boost productivity and efficiency in multiple ways that are synergistic."

"I don't want to compete with professionals and amateurs," Tom explained. "I want to augment and complement. Last week one AAVSONet scope here successfully responded to a GRB alert message and detected the event. Arne pointed out that many other big telescopes in North and South America also responded to the event, but that there is actually a smaller capability to perform multi-color imaging of these events in the northern hemisphere. Therefore, I've altered my filter script so that we only respond to GRB alerts north of +20 declination."

But sometimes, even nowadays, in this smartphone, smart telescope, automated world, we have to do things the old fashioned way. Get up in the middle of the night, open the observatory, point the telescope, acquire the data, examine the images and then close everything up when the sun rises.

Saturday evening, January 21, I got an email from Bob Moore, a member of the Puckett Supernova Search team, requesting follow up images of a small galaxy, UGC 9396, aimed at coordinates outside the center of the galaxy. None of the other recipients of the request had much hope due to poor weather at their sites, and I knew it was going to be cloudy in Michigan, so I told Bob I would try to get it in the queue for the AAVSOnet K35 telescope in New Mexico.

On Sunday the 22nd, I emailed Arne Henden, the AAVSO Director, and Tom Krajci to ask for a TOO (Target Of Opportunity) on the possible supernova. Tom indicated the weather was not looking great, but that he would monitor the situation. Arne’s message to Tom was clear. “If you are going to open, then I'd get a snapshot of this target. If you are planning on staying closed, I wouldn't do anything heroic.”

Just before 4AM EST Monday morning, Tom wrote to say he had opened up two of the telescopes and was going to try to get images of the possible supernova along with some other priority targets as long as the weather held out.

Tom picks up the story from there. “Before going to bed I reviewed satellite animation loops and it was apparent that the cloudy evening weather would clear off that night, but probably some time after 2AM.

I didn't set an alarm for 2AM, but I woke up anyway and was relieved to see that the clearing trend was happening, although not as fast as I would have liked. But the winds were not strong, air was dry, and there was no threat of precipitation...which made it 'safe' in my book to open scope shelters.”

Getting up in the middle of a cold winter night to fire up telescopes and computers to get these images acquired counts as heroic in my book!

Tom continued, “I only opened two of the seven operational shelters. The two scopes were K28 and K35, and they had imaging plans for new supernovae that needed confirmation. I stayed up just long enough to verify that they were running properly with good focus and pointing. The supernovae would not rise high enough until about 5AM, so I set the alarm for that time.

Checking image results at 5AM, the supernova for K28 had been imaged well, and it was a fairly bright object, not too close to the galaxy's core. We had good data for the night." But his work for the night wasn't over.

"The target for K35 was a different story. The object was much fainter and closer to the bright core, and inspection of the B filtered image showed unacceptable E-W smear. I increased exposure times and submitted the observing plan again, and went back to sleep. After sunrise I looked at the second set of images, which were better quality and a more appropriate exposure time.”

I saw his email message early Monday morning and anxiously waited for the image-processing pipeline at AAVSO to kick into gear. By 2:30 that afternoon, I had examined the images, determined a V magnitude and sent off a note to Arne, Tom, Bob, and the supernova discovery team that we had indeed confirmed their discovery. We were the proud parents of a 16th magnitude supernova, and the AAVSO robotic telescope network had acted as midwife in the birth.

SN 2012N in the galaxy UGC 9396

Early Tuesday morning, CBET 2991 landed in my inbox, announcing the discovery of another supernova by the Puckett Observatory Supernova Search Team, SN 2012N. We were happy to see credit given to the AAVSOnet telescope and glad to be part of another modest scientific discovery. Tim Puckett and his team score another supernova, and AAVSO gets the assist.

IW Andromedae is a Z Cam star!

2012-01-22T19:31:00.000-05:00

This is not a newsbreak. Taichi Kato, Ryoko Ishioka andMakoto Uemura described this system as a Z Cam dwarf nova back in 2003, in theInternational Bulletin on Variable Stars (IBVS).

http://www.konkoly.hu/cgi-bin/IBVSpdf?5376

Based on 55 observations made over a period of about fourmonths this team caught IW And in a standstill, which is the definingcharacteristic of Z Cam dwarf novae.

Light curve of IW And from Kato et al, 2003, IBVS 5376

Since the earliest days of the Z CamPaign http://arxiv.org/abs/1104.0967 I hadnoticed that the light curve of IW And was unlike that of any other system inthe Z Cam candidate sample. It exhibited a quasi-periodic behavior whose lightcurve looked more like an eclipsing system than a dwarf nova.

This never before seen behavior led me to believe thatperhaps we had discovered some new animal in the CV Zoo. "This doesn't look like a Z Cam light curve," I told myself. "We may have stumbled on to something important here!"

My ego quicklyoverruled the facts, and I have been hoping ever since that I haduncovered some unique, astrophysically interesting class of CVs. I convinced alot of people to pay special attention to this system, hoping that my“discovery” would pan out.

Fortunately, the stars couldn’t care less about my ego, andIW Andromedae has once again gone into a prolonged standstill, as evidenced by the AAVSO lightcurve, confirming that it is indeed a member of the Z Cam class of dwarf novae.

AAVSO light curve of IW And,

clearly showing the standstill after an active period of outbursts and quiescence.

Welcome to the club, IW And. I still think you are special,and you will remain one of my favorite variable stars forever.

As if to add to the lesson in humility, V513 Cas, my other "special case" appears to be in the early stages of a Z Cam standstill also!

A Z CamPaign update will be coming soon. In the meantime, thank you to all who have made this campaign a success and keep up the excellent coverage.

Adjusting the clock again

2012-01-22T11:06:00.001-05:00

Personally, I find Daylight Saving Time to be mostly an annoyance. I don't see why we need to spring forward and fall back every year. It gets dark earlier in the winter and later in the summer...big deal. It stays darker later in the winter and dawn breaks earlier in the summer. Yea, no kidding. To a farmer or amateur astronomer these things are a basic fact of life. If you want to send the kids to school in the light of day, they are going to have to leave later in the morning and get home by dinner time in the winter (in the northern hemisphere). There is nothing you can do to change that.

The length of day and the seasons has to do with the tilt of the Earth's axis and its annual trip around the Sun. This journey takes 364.25 days, so every four years we need to add a Leap Day to the calendar. You would think that this is all confusing enough. Changing the number of days in a year, switching time zones without moving twice a year, but now we have to adjust our clocks again!

On June 30, 2012, a “leap second” will be added to the world’s clocks at 23 hours, 59 minutes, 59 seconds Coordinated Universal Time (UTC). This corresponds to 7:59:59 p.m. Eastern Daylight Time, when the extra second will be inserted at the U.S. Naval Observatory’s Master Clock Facility in Washington, DC.

Historically, time was based on the rotation of the Earth relative to celestial bodies, and the second was defined in this reference frame. However, the invention of atomic clocks defined a much more precise “atomic” timescale and a second that is independent of Earth’s rotation. In 1970, an international agreement established two timescales: one based on the rotation of the Earth, known as UT1, and one based on atomic time, Coordinated Universal Time, or UTC. The International Earth Rotation and Reference Systems Service (IERS) is the organization which monitors the difference in the two time scales and calls for leap seconds to be inserted in or removed from UTC when necessary to keep them within 0.9 second of each other.

The common misconception is that the occasional insertion of leap seconds every few years indicates the rate at which the Earth's rotation is slowing. Now you know the real story.

Don't worry. Your work day isn't going to get any longer, and our calendar with all its warts and blemishes will continue to serve us well into the future. This tiny adjustment isn't going to have much, if any impact on your life. It might be interesting to watch your smartphone or GPSUTC clock do a slight hiccup just before 8pm on June 30th. For all my fellow obsessive compulsive friends out there, this is an excellent time to reset your clocks and watches to be strictly accurate.

I just hope I'm having a good day on June 30, because at 8pm I'm going to have to relive a whole second of it!

Carnival of Space #232

2012-01-15T12:41:00.000-05:00

Run, don't walk, to the latest Carnival of Space. This week's host is Vintage Space, a blog about the history of spaceflight and exploration. This is an excellent blog worth adding to your RSS feed or reader. The back story to how Amy came to create the blog and the overview of the history of spaceflight are themselves a great read.

Vintage Space will introduce you to this week's Carnival fare, which includes pieces about exoplanets, exomoons, supernovae, evasive action to avoid space collisions, an interview with a NASA astronaut, and the mythical planet Nibiru.

Step right up, get your tickets here. It's amazing, it's bizarre, it's the Universe! Carnival of Space #232, people. Enter and be enlightened.

Goldilocks Moons

2012-01-14T12:11:00.000-05:00

The search for extraterrestrial life outside our Solar System is currently focused on extrasolar planets within the ‘habitable zones’ of exoplanetary systems around stars similar to the Sun. Finding Earth-like planets around other stars is the primary goal of NASA’s Kepler Mission.

The habitable zone (HZ) around a star is defined as the range of distances over which liquid water could exist on the surface of a terrestrial planet, given a dense enough atmosphere. Terrestrial planets are generally defined as rocky and similar to Earth in size and mass. A visualization of the habitable zones around stars of different diameters and brightness and temperature is shown here. The red region is too hot, the blue region is too cold, but the green region is just right for liquid water. Because it can be described this way, the HZ is also referred to as the “Goldilocks Zone”.

Goldilocks Zones around various type stars. Credit: NASA/JPL- Caltech

Normally, we think of planets around other stars as being similar to our solar system, where a retinue of planets orbits a single star. Although theoretically possible, scientists debated whether or not planets would ever be found around pairs of stars or multiple star systems. Then, in September, 2011, researchers at NASA’s Kepler mission announced the discovery of Kepler-16b, a cold, gaseous, Saturn-sized planet that orbits a pair of stars, like Star Wars’ fictional Tatooine.

Tatooine- the Star Wars planet with two suns

This week I had the chance to interview one of the young guns studying exoplanets, Billy Quarles. Monday, Billy and his co-authors, professor Zdzislaw Musielak and associate professor Manfred Cuntz, presented their findings on the possibility of Earth-like planets inside the habitable zones of Kepler 16 and other circumbinary star systems, at the AAS meeting in Austin, Texas.

Kepler 16b Credit: NASA/JPL-Caltech

“To define the habitable zone we calculate the amount of flux that is incident on an object at a given distance,” Billy explained. “We also took into account that different planets with different atmospheres will retain heat differently. A planet with a really weak greenhouse effect can be closer in to the stars. For a planet with a much stronger greenhouse effect, the habitable zone will be further out.”

“In our particular study, we have a planet orbiting two stars. One of the stars is much brighter than the other. So much brighter, that we ignored the flux coming from the smaller fainter companion star altogether. So our definition of the habitable zone in this case is a conservative estimate.”

Quarles and his colleagues performed extensive numerical studies on the long-term stability of planetary orbits within the Kepler 16 HZ. “The stability of the planetary orbit depends on the distance from the binary stars,” said Quarles. “The further out the more stable they tend to be, because there is less perturbation from the secondary star.”

The habitable zone around Kepler 16 from Quarles et al

For the Kepler 16 system, planetary orbits around the primary star are only stable out to 0.0675 AU (astronomical units). “That is well inside the inner limit of habitability, where the runaway greenhouse effect takes over,” Billy explained. This all but rules out the possibility of habitable planets in close orbit around the primary star of the pair. What they found was that orbits in the Goldilocks Zone farther out, around the pair of Kepler 16′s low-mass stars, are stable on time scales of a million years or more, providing the possibility that life could evolve on a planet within that HZ.

Kepler 16b’s roughly circular orbit, about 65 million miles from the stars, is on the outer edge of this habitable zone. Being a gas giant, 16b is not a habitable terrestrial planet. However, an Earth-like moon, a Goldilocks Moon, in orbit around this planet could sustain life if it were massive enough to retain an Earth-like atmosphere. “We determined that a habitable exomoon is possible in orbit around Kepler-16b,” Quarles said.

I asked Quarles how stellar evolution impacts these Goldilocks Zones. He told me, “There are a number of things to consider over the lifetime of a system. One of them is how the star evolves over time. In most cases the habitable zone starts out close and then slowly drifts out.”

During a star’s main sequence lifetime, nuclear burning of hydrogen builds up helium in its core, causing an increase in pressure and temperature. This occurs more rapidly in stars that are more massive and lower in metallicity. These changes affect the outer regions of the star, which results in a steady increase in luminosity and effective temperature. The star becomes more luminous, causing the HZ to move outwards. This movement could result in a planet within the HZ at the beginning of a star’s main sequence lifetime, to become too hot, and eventually, uninhabitable. Similarly, an inhospitable planet originally outside the HZ, may thaw out and enable life to commence.

“For our study, we ignored the stellar evolution part,” said lead author, Quarles. “We ran our models for a million years to see where the habitable zone was for that part of the star’s life cycle.”

Being at the right distance from its star is only one of the necessary conditions required for a planet to be habitable. Habitable conditions on a planet require various geophysical and geochemical conditions. Many factors can prevent, or impede, habitability. For example, the planet may lack water, gravity may be too weak to retain a dense atmosphere, the rate of large impacts may be too high, or the minimum ingredients necessary for life (still up for debate) may not be there.

One thing is clear. Even with all the requirements for life as we know it, there appear to be plenty of planets around other stars, and very likely, Goldilocks Moons around planets, orbiting within the habitable zones of stars in our galaxy, that detecting the signature of life in the atmosphere of a planet or moon around another Sun seems like only a matter of time now.

SN 2012A--and the winner is...

2012-01-13T06:48:00.000-05:00

As I wrote in Supernova Alphabet Soup in late December, each year there is an unofficial contest here at Simostronomy, where we wait in anxious anticipation of the first named supernova of the new year. This year's winner has finally been announced, SN 2012A was discovered on January 7th by Bob Moore, Jack Newton and Tim Puckett shining at magnitude 14.6 in galaxy NGC 3239. The variable was designated PSN J10250739+1709146 when it was posted at the Central Bureau's Transient Object Confirmation Page webpage, and has now been designated SN 2012A based on spectroscopic confirmation.

Discovery image of PSN J10250739+1709146

Puckett Observatory Supernova Search

A spectrum of PSN J10250739+1709146 (SN 2012A) obtained on Jan. 10 by T. Pursimo with the Nordic Optical Telescope, shows it to be a type-II supernova soon after explosion.

This is another fairly bright supernova caught early in its eruption, so we are off to a flying start for 2012. My own observation on January 11th of 13.748V, taken with one of the AAVSOnet telescopes, shows the supernova has brightened considerably since discovery.

NGC 3239, also known as ARP 263, is a highly disturbed and irregular galaxy. It is located in the constellation Leo, at a distance of about 49 million light-years. The galaxy shows the effects of interaction with another galaxy.

NGC 3239, host galaxy to SN2012A

Image credit: Bob Franke

The Meeting Attendee Bill of Rights

2012-01-12T10:19:00.001-05:00

I've been in Austin for four days now, attending astronomy workshops, talks and poster sessions at the 219th Meeting of the American Astronomical Society. For the most part, it's been very interesting, informative and fun. But there is something that has been growing inside me since I attended my first meeting many years ago, and I just can't take it any more. That's right, I'm fed up, and I'm not going to take this any more!

"I'm mad as hell, and I'm not gonna take this anymore".

The simple truth is, some people should have their public speaking licenses revoked. They show up at every meeting and make us suffer through their ill-conceived and terribly executed presentations. They show no regard for our feelings or sanity, and unapologetically waste our time over and over again. You know who they are. They are the same people all the time.

Monotone Mark- This guy is so dull he can take the shine off your shoes. His deadpan, lifeless expression and monotone delivery is enough to turn your mind to jelly. He may be a brilliant scientist, but listening to him is boring and painful. He acts as if he doesn't even care about what he is talking about. I just want to scream after about three minutes, "Look, dude. If you don't care about what you're talking about, why should I?"

Unprepared Ursula- Everyone knows how much time they have been given. At an AAS meeting, most papers are only given ten minutes, which includes time for questions after. You need to consolidate your slides, trim your content and get to the heart of the matter, including your conclusion, in 5 or 6 minutes. You don't have time to do thirteen slides explaining what gave you the idea to run your experiment. Ursula is always so surprised when the session chair gives her the one minute left signal and she realizes she still has 142 slides to go. So NOW she begins to edit her presentation right in front of us, skipping the less important slides and racing through the rest, trying in vane to convey her point as the sand runs out of her hourglass. BING! Guess what? Your time is up and you are an idiot.

Eric the Excited- Eric starts off in high gear. He is so excited to be here. He's had ten cups of coffee. It's amazing how fast he can talk. He is going to show us 142 slides in three minutes. I once saw him go so fast he suddenly disappeared right in front of us. All that remained was a mosquito-like buzzing, like in the Star Trek episode where they got sped up into another dimension.

Ummer the Bummer- Ummer cannot complete a sentence or thought without saying the word "umm" somewhere. He begins his umm talk, by showing us umm his first umm slide, which is a graphical depiction umm of umm whatever umm he was umm umm umm ummmmummummmmm. Just shoot me.

Vladimir Vladimoshkadorbadovski- Vladimir is a renowned scientist from the old country, whose papers are informative and well written, but his accent is so thick it's not really English. He knows his stuff, he doesn't stammer, he's well respected in the field, I just didn't understand a word he said. Someone needs to be honest and tell Vladimir his English is not good. He might as well have given the talk in his native tongue and supplied subtitles in the slides.

This is all particularly egregious in light of the fact that we have invested a substantial amount of time and money to travel to these meetings, stay in hotels nearby and pay meeting registration costs. I think it's time we created a Meeting Attendee Bill of Rights. We the many, have been abused by the same few for so long that it has become our duty to rise up and declare ourselves free from the abuse of those who disrespect our valuable time and feelings.

The Meeting Attendee Bill of Rights

We, the audience of presentations at meetings, conferences and other gatherings have the right to expect our presenters to act in a professional and engaging manner, up to and including the following:

1- Speakers should be at least mildly interesting to listen too. Voice modulation and inflections are not optional. Mumbling and/or monotone delivery is not allowed.

2- Speakers should be well-prepared. Practicing your presentation in advance so that it can be given in the time allotted is not just a good idea, it is required. Practice will enhance your confidence and improve your delivery.

3- Speakers should deliver their content at a pace that can be comprehended. If you are so nervous you think you need to speak at 100 miles per hour, see number 2.

4- Speakers will not interrupt their sentences while thinking about the next words to come out of their mouth. Again, see number 2.

5- Speakers will have mastered the art of speaking in the language of the meeting or else provide a translator, subtitles or a stand in to replace them.

Failure to meet any of these requirements will result in a partial or full refund of the conference or meeting registration cost. You can't give me back the ten minutes of my life you just wasted, but you can give me my money back, and you will.

"We're mad as hell and we're not gonna take this any more!"

AAS Meeting- Sunday Workshops

2012-01-09T13:16:00.000-05:00

The Austin Convention Center

Austin, Texas- After traveling to Austin on Saturday, I found myself up early grabbing a free breakfast in the hotel Sunday and rushing over to the Austin Convention Center to catch the first of two workshops on the Virtual Astronomical Observatory. The first workshop was for educators, focused on the World Wide Telescope (WWT) and its potential uses in the classroom.

WWT is essentially a planetarium program enhanced with images from ground based telescopes, the Digitized Sky Survey, the Hubble and Spitzer Space Telescopes as well as collections of satellite images from spacecraft around other planets.

The Ring Nebula (M57)

WWT is a powerful teaching tool. Users can create dynamic, interactive Tours of the Universe, which can be shared with friends, used in schools or as part of a public presentation and they can be shared online. The tour they used to demo this feature to us was created by a six year old named Benjamin. He did a tour of the Ring Nebula in Lyra, starting from his home in Toronto, Canada, zooming out past the moon and flying to the constellation Lyra, finally zooming in on M57, all the while with narrative supplied by Benjamin, who I must admit, had a cuteness factor off the charts.

The features I was mostly interested in were not available as standard tools in WWT, but could be added later as data sets. Things like variable star catalogs, supernovae positions and images, and star catalogs going much deeper then Hipparcos and Tycho. I spent most of the interactive period talking with the software developer about the possibilities of further data sets. We discussed the possibilities for using this virtual telescope for training new AAVSO members and observers concepts in stellar evolution, distances in the universe and stellar population studies. We could create tours that were specifically AAVSO branded that could be released publicly as part of an education and outreach effort.

The late afternoon session of the workshop was aimed at researchers and dealt with the powerful new tools available in the Virtual Astronomical Observatory (VAO). The VAO is part of a worldwide effort called the Virtual Observatory (VO) whose aim is to link astronomical data and services worldwide.

The VO environment is designed to facilitate astronomical research with a speed, efficiency, and effectiveness not previously possible, and it will be available to researchers around the globe regardless of their affiliation or access to observing facilities. The VO has the potential to provide a powerful resource for initiatives in education and public outreach. The US Virtual Astronomical Observatory (VAO) is the VO effort based in the US, and it is one of many VO projects currently underway around the world.

I've been hearing about the potential of the VO and VAO for over a decade now, and I can understand how it is supposed to work, but it seems to be taking a long time to live up to its potential, and as far as I can tell, it is not heavily used in the ways it was intended yet. Some of it may have to do with the complexity of the tools and user interface. What I found out yesterday was that part of the problem may be that the people working on the project, while brilliant software designers and experts in their fields, are some of the worst presenters I have come across at an astronomy conference.

In spite of the fact I came a day early specifically to take in these two workshops, I had to leave after the second presenter. I was sure I was about to pass out from boredom, or die as my head imploded from the monotone delivery destined to shrink my brain. My disappointment in the oral presentation skills of astronomers in general will be the topic of another blog.

Spreading the Word

2012-01-03T13:59:00.001-05:00

One of the things I enjoy doing most is acting as a spokesperson for the AAVSO and sharing my knowledge, experience and enthusiasm about variable stars, observing and the AAVSO with other people. I write blogs, newsletter pieces and articles that reach a lot of people, but there is nothing like the experience of meeting new people face to face and watching their eyes light up as you explain variable stars and stellar evolution, or the seeing light go on as they realize, "Hey, I could do this too!"

This year (2011) I've been able to reach a lot of people this way. I gave a talk entitled "Stand Back, We're Going To Try Science!" about CCD observations of variable stars to a packed house at the Northeast Astro Imaging Conference in New York. I gave the same talk via Skype later in the year for the Orange County Astronomers. I wasn't sure how effective that was going to be, but the lively question and answer session after the talk let me know it was a success.

In June I gave several talks at the Texas Star Party and got to meet and hang out with a lot of serious visual observers with ginourmous telescopes. I had a great time talking about 100 years of the AAVSO at the Nebraska Star Party in August, and recently I went to St. Louis to meet with members of the St. Louis Astronomical Society, tour their observing facility out in the countryside, and give a talk entitled "Advancing Variable Star Astronomy", about the AAVSO's role in variable star research over the first 100 years of its history.

Every audience is different, but they all have a few things in common. First, they are all interested in astronomy and knowing more about the universe we live in, or they wouldn't be there. Second, they have a high regard for the AAVSO, even if it's just through things they've heard. Last, but not least, when effectively presented to them, audiences are very interested in what are variable stars, why are scientists interested in them, and how do they fit into the landscape of astronomy in general.

Then, if you're lucky, there are a few who want to know how they can join in the fun and contribute to science. Not everybody wants to be an active variable star observer or data-miner, but the interest in what we do is there.

This is why our Speakers Bureau is so valuable. We have a number of AAVSO members who give dozens of talks every year to astronomy clubs, societies, schools, scout troops, planetariums, star parties and conferences. They are out there spreading the gospel about variable stars, citizen science, AAVSO and the role amateurs can play in supporting and contributing to science. These ambassadors of VSO are available at little or no cost to the public. If you'd like to have one of us give a talk to your local group, fill out the form at http://www.aavso.org/contact.

If there is no one available for your area, we also provide pre-made PowerPoint presentations that you yourself can download and use to give a talk to your club or school. We have a whole library of presentations to choose from. We might even be able to custom design or create one for you. Write to us and let us know what you need. We are here to help. It's never been as easy as it is today to get someone to give an inspiring and entertaining talk at your next meeting.

Carnival of Space #230

2012-01-02T08:28:00.001-05:00

Harlequin's Carnival by Joan Miro

The Carnival of Space keeps rolling along. This week's version is number 230 in the series. The Carnival of Space is a weekly collection of pieces from the astro-blogisphere, gathered up under one roof for your reading, or listening, pleasure.

This week's Carnival is hosted by Cheap Astronomy, Steve Nerlich's blog, where you can learn about how to do astronomy on a shoestring budget. Steve offers you the text version here, or you can listen to the Carnival as a podcast here.

If you'd like to contribute to the Carnival of Space or host a Carnival, contact Brian Wang of Next Big Future at blwang@gmail.com.

2012 Looking Ahead

2012-01-01T13:53:00.000-05:00

First things first- Happy New Year and thank you for supporting the Simostronomy blog week after week.

It's the first day of a new year and some things here have already changed for 2012. The look and feel of the blog, for example. I had considered giving the blog a facelift but wasn't sure which direction to go. Fortunately, Blogger has come out with a bunch of new templates, and I particularly liked the idea of this one, where you, the reader, get to choose the look and feel of the site according to your taste. What a brilliant idea!

Who am I to force you into some convention I am comfortable with? The new Simostronomy blog gives you seven options to preview and display the various articles contained here.

The Classic look just lines them up in reverse chronological order from top to bottom, showing the whole article. Flip Card shows an image that flips over to the title and date of each piece as you mouse over. Magazine, my new personal favorite, shows one large feature article preview box (most recent) a line of second tier article previews and then more and more arranged somewhat randomly as you scroll down the page. It would take me a lot of work to keep this fresh and randomized looking, so I really appreciate this view. I can concentrate on simply writing, and not worry about web page layout so much.

Mosaic is interesting, but I don't like the way the images get cropped and there isn't enough information in the preview to get me excited about reading any of the pieces. But again, that's me; maybe you like it. If so, great- enjoy. Sidebar is a good look, but I don't like the text color in the titles on the left. I'd like it to be easier to read, but haven't figured out how to edit that yet. I don't really get the Snapshot mode. It just previews all the pictures from all the articles, and I don't think that's very helpful navigation-wise. Your mileage may vary. Last but not least, Timeslide is a very nice way to lay out the pieces, but the text versus background color needs to be adjusted for easier reading. If not for that, this might be my favorite view.

I'll work on it as time allows, so consider it a work in progress. If your'e a Blogger maestro and you have any tips or tricks regarding this template, add them as comments to this piece, please. I can use the help.

The new look is one thing. I'm also looking forward to getting back to writing a lot more than I did in 2011. My workload and travel schedule just got out of hand, and unfortunately, the blog was one of the casualties. I also took on some extra projects and saw those through to completion. I've learned my lesson ( I hope) and have already said no to two interesting proposals since December 1. I just can't add anything else to my plate right now if I want to do the things that are important to me. High on that list is writing this blog, and finishing my big Z Cam research paper in early 2012. I've given myself a deadline of leap year day, February 29th.

I'm going to try to limit my travel as much as possible, but I don't seem to be succeeding at that yet. I'll be going to Austin, Texas next week for the AAS meeting, we're going to Florida for the Winter Star Party in February and I'm already booked to return to Boston in March. We'll just have to see how spring and summer shape up. If I can keep my resolutions, you'll be reading about it all here.

Once again, thanks for your loyalty. I'll try to do a better job of deserving your readership this year.

Supernovae Alphabet Soup

2011-12-28T09:30:00.000-05:00

SN 2011fe aka PTF11kly
Image: Wikipedia

The International Astronomical Union (IAU) is the sole body responsible for the official naming of astronomical objects. So if you have a problem with the way things in the Universe are named, you now know where to send your email and letters of protest.

Before we get into this, a quick grammar note. When we discuss more than one supernova, they are called supernovae (super- no- vee), not supernovas. The same holds true for more than one nova. They are novae (no- vee). Please don't write and ask me about Novas. Those are old Chevrolets, not stars.

Fortunately, the naming convention used for supernovae is pretty simple and straightforward. The name is formed by combining the prefix SN, for supernova, the year of discovery and a one- or two-letter designation. The first 26 supernovae of the year get an upper case letter from A to Z (SN 1987A). After that, we start over with pairs of lower-case letters are used, starting with aa, ab, and so on (SN 2005ap).

Of course there are exceptions, there are always exceptions. That's one of the things about astronomical nomenclature that is maddening, but I digress...

Four important historical supernovae are known simply by the year they occurred- SN 1006, SN 1054, SN 1572 (more commonly referred to as Tycho's Nova), and SN 1604 (also known as Kepler's Star).

One reason I'm bringing this subject up now is that we are ending the year, so we are approaching the time where we reset the naming schema for 2012 and the first supernova of the new year will get named SN 2012A. With the annual number of discoveries rising each year to well over 500, it is always a bit surprising how long it takes for that first one of the year to get named. So each year we hold an unofficial contest here on Simostronomy to see who will discover the first SN of the new year.

One of the reasons it usually doesn't occur on the first day of the year is that supernova discoveries have to be officially confirmed spectroscopically before they get an official IAU designation. When someone discovers a possible supernova it gets reported to the IAU and then listed on the CBAT Transient Objects Confirmation Page. If it is a possible SN it gets a temporary designation of PSN (possible supernova) followed by its coordinates (PSN J01560719+1738468).

Only after someone has taken a spectrum confirming it is a supernova does it get a name with the year and letter combination. This can take several days, so it is unlikely a SN discovered on January 1 will be named until later in the week or the second week of the month. If it were discovered on December 23rd and confirmed on the 1st of January it would still get a name from the previous year.

This time lag will not be acceptable in the near future, with surveys like LSST coming on line. Astronomers will want immediate notification of discoveries of all types of transient objects including supernovae, so what has happened is new groups searching for SNe have begun to make up their own names.

The Catalina Real Time Survey is one such group. They are discovering dozens of possible supernovae that don't always get official IAU designations. Their discoveries are all named CSS (Catalina Sky Survey) followed by the date in yymmdd format and then the rough coordinates, like this CSS111227:104742+021815. Crazy, huh?

ROTSE, the Robotic Optical Transient Search Experiment, also discoveries SNe and gives them their own designation in the form of ROTSE3 (the third iteration of this experiment) followed by coordinates, such as ROTSE3 J133033.0-313427.

And there is the Palomar Transient Factory which names its discoveries with the prefix PTF of course, such as PTF11kly, the nearest supernovae in decades, visible with small telescopes in M101. This SN eventually received an IAU designation, SN 2011fe, but that just created more confusion, since now it is known variously by both names in the literature.

Somehow managing to keep it all together amidst the confusion, David Bishop maintains the Latest Supernova Website where you can see discovery images and keep track of your favorite supernovae and related news. There is an excellent article about David and how his website evolved from simple beginnings.

So if you're asking WTF? about the latest SNe the on the WWW the URL that will lead you through the ABC's is definitely http://www.rochesterastronomy.org/supernova.html.

Got that? Good, there will be a quiz later...

Top Ten Things I Didn't Get For Christmas (That I Really, Really Want)

2011-12-27T12:01:00.004-05:00

The Top Ten Things I Didn't Get For Christmas (That I Really, Really Want)

#10- Bluetooth headset for hands free phone calls in the car- I drive back and forth to Boston several times a year and have been driving a lot of 6-16 hour trips. Talking on the phone is actually a good use of my time when I'm stuck in the car. I can catch up with friends, family, and associates as the odometer spins and I blow past the state police.

#9- iPad or an Android tablet- I'd be happy with ether one, I think. An iPad would give me access to some of the cool Apple apps I don't have, but to be honest, I love my Droid phone so the ASUS Transformer Prime tablet would be fine.

#8- A new car- Hey, why not? So I can talk on the phone in comfort, right? I'm thinking maybe an mid-sized SUV like the Acura MDX or something with better mileage in a two wheel drive. It has to be sporty and fast. The S in SUV stands for sport. I won't give up my need for speed for the cargo room. My fall back position is to get a sexy red convertible that will advertise my full blown mid-life crisis.

#7- 15 x 70 binoculars- If I had a larger pair of binos and a stand I might just take them to the next star party, instead of lugging all that gear for a change. Then I could go around looking through everyone else's scopes at deep sky objects.

Wait... nah, that doesn't sound like me. No, I'd spend the night observing bright variables with the binoculars. Who am I trying to kid?

#6- Paramount MX- Advertised as slightly smaller than a Paramount with a 90 pound capacity, this mount is now about as much mount as you can buy without spending 6 figures.

#5- Celestron 14" SCT- It doesn't have to be one of the new EdgeHD optical tubes (although that would be nice, since I already have the CGE Pro mount). I'd settle for one of the older carbon fiber tubes or even an old orange beast. Just something slightly bigger to go on my new Paramount MX.

#4- Software- (TheSky, Maxim DL, ACP) This is the software suite I would need to make my system run unattended all night while I observe visually. Pretty sure I will never get there without a serious investment in software.

#3- Telelvue 10mm Ethos eyepiece (6mm and 17mm too!)- I tried one of these out at the Texas Star Party in 2011 and it blows away any eyepiece I have ever seen, used, tested or dreamed of. 10mm gives a high enough magnification that the sky background is truly nice and dark, enhancing contrast and making it easier to see faint stars and objects. The field is remarkably flat and the anti-reflective coatings so superior to even my best Nagler eyepieces that I was sold after about two minutes of a head to head comparison.

I think if I had the 17mm and 6mm Ethos I would never need any other eyepieces, so throw those in my Christmas stocking as stuffers too, please.

#2- More clear weather at home- My supporting evidence may be anecdotal and unscientific, but I swear winter has sucked twice as bad as ever the last five years. December has always been a crappy month for cloud cover, but January used to be one of my best months, and I was never completely skunked from October to March like the last few years. El Nino or whatever, please come back and clear up these long winter nights for me. I miss the winter sky!

#1- More time- More than anything else, what I really need is more time. There is so much I want to do. More time with my wife, son and grandkids. More time to futz around the garden and my house. More time to read and write research papers. More time to write blogs and podcasts. More time to visit with friends. More time to get all the things I want to do at work done and still have time to do anything else! My rough calculation is that I need about 42 hours in a day and 8 days in a week. I guess what I really need is to live long enough for us to discover and colonize a planet around another star with that rotational period.

Yup, more time. That's what I really need.

2011 Variable Star News in Review

2011-12-26T11:54:00.001-05:00

For most of us in the AAVSO, 2011 will hold a special place in our memory as the Centennial Year of the AAVSO. We had fundraising events, special features on our website, contests, two very special meetings and a book published on the history of the AAVSO. We also passed a couple milestones in our database.

It all started early in January as we launched all the special centennial features and pages on our website. We were closing in on 20 million observations in the database, so we held a contest to see who could predict the exact data and time we would cross that magic mark. On February 19, 2011 we passed the 20 million mark just as Chris Watson had predicted. (I came in third in the informal contest for my guess of March 3).

Also in February, an extremely bright outburst of one of the Sloan CVs was detected by Jeremy Shears of the the UK. He discovered SDSS J133941.11+484727.5 in outburst at magnitude 10.5, which indicated to those of us in the know that we had a new WZ Sagittae type dwarf nova in our midst. Exciting news for us CV junkies. This star had already proved interesting by the fact it had a pulsating white dwarf as its primary. So an outburst of this amplitude would provide a chance to investigate how the increase and then decrease in temperature might affect this pulsation.

AAVSO observer Michael Linnolt

Our hearts really started to pound in April, when Michael Linnolt of Hawaii, discovered T Pyx in outburst, after a prolonged period of quiet. T Pyx is a recurrent nova that had undergone eruptions every 20-30 years or so. But the last eruption was in 1966, so it was long overdue. Various scientists had put forth theories on why this was so, and even predicted that it would be centuries before it went off again, so of course T Pyx decided to throw a wrench into the whole theory and go into outburst in 2011 after 45 years. This led to a world-wide campaign similar to the U Scorpius campaign the year before. T Pyx is still fading from this most recent outburst as you can see from the AAVSO light curve.

2011 AAVSO light curve for T Pyx

AAVSO attendees in front of the Boston Public Library
May 2011

In May, the AAVSO 100th Spring Meeting was held as a joint meeting with the American Astronomical Society (AAS) in Boston. Our meeting started Saturday afternoon with an AAVSO Paper Session and the AAVSO banquet. Sunday included a morning AAVSO Paper Session, an afternoon joint session with the AAS Historical Astronomy Division, and the AAS Welcome Reception. Monday were two topical plenary talks on variable star science as well as 2 AAVSO-sponsored, variable star special sessions, "Astrophysics with small telescopes" and "Variable stars in the imaging era". I gave a talk on my Z CamPaign during the small telescopes period. Monday evening we held an open house at AAVSO HQ.

As the end of the epsilon Aurigae eclipse approached in May, Citizen Sky began to concentrate on analysis of the data from the two year long eclipse. One of the terrific results of the Citizen Sky project is this awesome light curve representing observations by thousands of observers around the world in many different wavelengths.

The first week in June I was at the Texas Star Party to give a talk on variable objects in or near deep sky objects. Some of the examples I gave were supernovae in well known galaxies. As if to prove my point, the heavens produced the first of two bright supernovae this year the day after my talk, SN 2011dh in the Whirlpool Galaxy, M51.

SN 2011dh
Image credit: Martin Mobberly

In August the second bright supernovae appeared in M101, just in time for my annual starbeque. A lot has been written about SN 2011fe, because it is the brightest and closest supernova to Earth in more than three decades. What's more, the explosion was caught well in advance of maximum light so astronomers have been able to witness almost the entire process in great detail.

Image by B. J. Fulton, Las Cumbres Observatory

Global Telescope Network.

September brought the discovery of yet another incredibly bright UGWZ dwarf nova by Hideo Nishimura, from Japan. The new variable star was detected at magnitude 11.8 in the constellation Draco. Unfortunately named PNV J18422792+4837425, this variable turned out to be a UGSU, meaning it exhibits "superhumps" in outburst.

For a whole week in October, the AAVSO celebrated its 100th birthday in style. We dedicated our new headquarters in Cambridge, MA, and celebrated the completion of renovations to the building resulting in a new conference center, historical archives, a guest suite for visiting astronomers, a residence for the Director and extensive improvements to the exterior of the building. We held an extended meeting featuring historical and scientific talks, and enjoyed a terrific closing banquet and awards ceremony featuring renowned astronomer Owen Gingerich, himself a lifetime AAVSO member.

As if that weren't enough, on October 25th Michael Linnolt hit pay-dirt again when he detected the long quiescent BW Scl in outburst, resulting in yet another world-wide campaign to observe this first time ever outburst.

As we raced towards the finish line, the "obzometer" on the International Database turned over once again as we passed the 21 million observation mark in December.

The AAVSO International Database
continues to grow at an astronomical rate
(pun intended)

No one knows what 2012 has in store for us, but you can be sure the Universe will have its share of surprises and wonders. The beauty, mystery and unpredictability of her variable stars is what keeps me and others coming back for more, year after year.

A Variable Star Index (VSX) Milestone

2011-12-23T10:13:00.000-05:00

VSX now contains information on 200,000 stars

December 22, 2011 the Variable Star Index (VSX), the most complete up to date resource for variable star information on Earth, reached a milestone as we passed the 200,000 mark for variable stars included in the database. The brainchild of Christopher Watson, and donated to the AAVSO, the VSX catalog has been growing steadily over the past few years, with hundreds of new entries, submitted one at a time, and data from surveys being uploaded en masse.

In the past year the database has gone through a radical transformation, as Sebastian Otero has spent countless hours cross-checking, eliminating duplications and errors and making dozens of corrections to the existing data, all while moderating submissions of incoming data along with the other moderators of VSX. So this milestone is significant in that we are reasonably sure we actually have 200,000 individual entries in VSX.

Another important development that will be announced in the coming weeks, is the creation of a document describing all the variable types contained in VSX, which is part of a larger vision leading to the standardization, more or less, of variable star nomenclature world-wide. I will have more to say about all that n 2012. For now, congratulations to the AAVSO and the VSX administrators and moderators for a job well done.

Berto bags another one!

2011-12-22T16:38:00.002-05:00

An IAU Circular landed in my inbox yesterday, announcing another supernova discovery. I don't normally get too excited about such things because they are not particularly rare any more and most of them are quite faint, 18th magnitude and fainter. Every once in a while a bright one pops up, and if it is brighter than 14th magnitude the AAVSO sends out an alert notice for our observers to observe it and report data to the International Database.

Discovery image of SN 2011ja
Credit: Berto Monard

The subject of this circular was around 14th magnitude so it got my attention, and then I saw it was discovered by South African amateur Berto Monard, who I have featured here on the blog in the past- Berto Monard- First Magnitude Amateur Astronomer. When we last talked he was closing in on 100 supernova discoveries, so I sent off a quick email to ask him how many this made.

Berto wrote back a short while later to tell me this is his 116th discovery! And he has another one in the queue that is just waiting for spectroscopic confirmation and follow up.

I told you he was incredible.

Northern R Cor Bors: The Good, the Boring and the Unknown

2011-10-15T14:24:00.000-04:00

Introduction

R Coronae Borealis stars (RCBs) are a small group ofhydrogen poor, carbon rich supergiants that decline in brightness unpredictablyand rapidly by up to 9 magnitudes, and remain at or near minimum light forseveral weeks or months, even years in some cases. It is generally acceptedthat the declines are the result of the formation of a cloud of carbon sootthat obscures the stellar photosphere, and that this condensation takes placein matter that has been ejected from the stellar surface toward the observer.

Some RCBs exhibit more or less regular variations that maybe interpreted as pulsations. The amplitudes of these changes are small, on theorder of a few tenths of a magnitude, and have periods of approximately 30 daysto 150 days. This pulsation appears to have no relationship to the obscuringevents, and has been seen to continue through fading episodes in several cases.

Possible evolutionary tracks

RCBs are intriguing because they challenge our models forstellar structure and evolution. At first, they were believed to be highlyevolved post-AGB stars, but most scenarios fail to explain the hydrogenabundance or trace their evolution back to the AGB.

Two more recent ideas suggest that 1) these may be ‘bornagain’ planetary nebula, created when the last thermal pulse is delayed to thepoint that it occurs as the star reaches the white dwarf phase. If the pulse isintense enough it may re-ignite a helium burning shell and expand the star togiant dimensions, moving it to the AGB for a second time, or that 2) RCBs maybe the result of the merger of helium and CO white dwarfs. The merger theorygoes a long way to explaining the exotic chemical composition of these stars.

The Family

Whatever their origin, this is a small group of unique,unpredictable stars, just my cup of tea! I’ve come to know many of them wellthrough a decade of observations and I have subdivided the class into my owncategories based on their relative activity and interest as targets for thevisual or CCD amateur astronomer or hobbyist. I call them simply the Good, the Boring and the Unknown. Letme introduce you to the ‘family’.

The Good

These are stars that provide a lot of entertainment valuefor the time invested in observing them. They are quirky and unpredictable, butmost importantly, they are active. You don’t need to wait five years to see afading event or some small blip in a light curve. These stars are crazy and notafraid to show it.

DY Per

02 35 17.07 +56 08 44.7

Spec. type C4,5(R8)

Mag. range 10.6 - <13.2 V (16.5V aavso)

DY Per from 1992 topresent

While this is certainly the light curve of an unpredictablestar, the fading episodes to don’t follow the typical RCB pattern. Is DY Per aspecial case in a class of special cases? Instead of occasional fades every fewyears or so, lasting months at a time, these episodes are more or less regularand spend almost no time lingering at minimum or maximum light.

For the visual observer with a 10” or 12” telescope thisstar is visible during all but the very faintest excursions into 15^thto 16^th magnitude range, and as you can see, it will soon be back upif you just wait a couple weeks. DY Per is a solid performer and always a surprisefrom night to night.

SU Tau

05 49 03.73 +19 04 21.8

Spec. type G0-1Iep(C1,0 HD)

Mag. range 9.1 - 16.86 V (18.2V aavso)

SU Tau from 1987 topresent

Discovered by Annie Jump Cannon, SU Tau is anotherentertaining star to follow. The AAVSO light curve for this one goes back to1909. As you can see from the above light curve, SU Tau has been very activesince 1994, with an extended period after an initial fade where it tried toclimb back to maximum light in fitful starts but sputtered again and again. Itis now recovering from the third fading episode in the last decade. As with DYPer, visual observers can follow all but the very faintest periods of thisstar’s unpredictable cycles.

Z UMi

15 02 01.48 +83 03 48.7

Spec. type C

Mag. range 10.8 - 17.5: V (18.5V aavso)

Z UMi from 1999 topresent

Z UMi is another RCB that delivers a lot of action. Becauseit is circumpolar, the light curve is nearly continuous. As shown in this lightcurve, the fading episode prior to the current one was a record breakingaffair, reaching an unprecedented minimum level and an extremely long, slowclimb back to maximum light. After a typical interval at maximum light, Z UMiprecipitously faded again and is currently recovering towards maximum. There isno guarantee it will make it to the top before sputtering or fading again, andthat is what makes observing these stars on a regular basis so much fun.

R CrB

15 48 34.41 +28 09 24.3

Spec. type C0,0(F8pep)

Mag. range 5.71 - 14.8 V (15.4V aavso)

Thirty years of R CrB

The prototype of the class, R CrB is a binocular starhovering around 6^th magnitude most of the time. Then, unpredictablyit fades rapidly, diving for cover in the inner sanctum at or near 14^thmagnitude. However, we live in interesting times, because the last fade of RCrB was one for the record books. In July of 2007, R CrB began to drop. ByOctober it was 14^th magnitude, but R CrB was only beginning to puton the show of the ages. In February 2009 observations of 15^thmagnitude began to come in, with no sign of a recovery. In fact, R CrB did noteven get back to 14^th magnitude until November of 2010. This fadewas not only the deepest in recorded history, it was now the longest, and itisn’t over yet!

Observations in June put R CrB around 12.2 V as it slowlymakes its way towards recovery. Will R CrB make a full recovery, or have arelapse and fade again before reaching maximum light. Only time and AAVSO datawill tell. No wonder this is one of the most well observed stars in the AAVSOprogram. You can’t buy this kind of reality entertainment.

ES Aql

19 32 21.62 -00 11 30.9

Spec. type C

Mag. range 11.5 - <17.7 V

All the AAVSO ES Aqldata, 1999 to present

Located on the celestial equator, this under-observed staris somewhat difficult for northern observers to monitor, including me, which isa shame because this is a great star to follow, if you can. That’s why I addedit to my AAVSOnet queue to acquire CCD photometry of it on a regular basis. Asluck would have it, just about the time I began obtaining CCD measures it wentinto the deepest death spiral in AAVSO recorded history, hitting 16.5V inFebruary 2011. I watched it steadily recover to 13.7V in May only to witnessanother fast decline, again reaching 16.5V as I write this piece, on June 27,2011. During this entire period I was the only one collecting data on thisfascinating star.

This is another fun to observe, unpredictable star worthputting on your program if you can observe near the celestial equator in Aquilafrom your observing site. I have it on both my visual and CCD programs.

U Aqr

22 03 19.70 -16 37 35.3

Spec. type pec

Mag. range 10.6 - 15.9 V

U Aqr AAVSO data from1976 to present

The AAVSO data for this star stretches all the way back to1905. Not surprisingly, at minus 16 degrees declination in Aquarius, it is nota well-observed star by northern observers. The long-term nature of U Aquarii’sbehavior seems to change each decade. From 1976 to 1986 it had 4 or fivefadings, then from 1986 to 1998, it remained more or less at maximum except fora couple seasons where it averaged one magnitude fainter than maximum light.Then, in 1999, it faded to fainter levels than ever seen before and has had adecade of fitful recovery to maximum light, which is where it was when I addedit to my robotic telescope queue.

Again, my beginner’s luck has struck gold. As soon as wepicked it up coming out of conjunction I could see it was fading to a deepminimum again, and as of right now the Krajci 35cm telescope holds the recordfor the faintest recorded magnitude of U Aqr in the AAVSO database, 17.2V onJune 26.

Obviously, a CCD target when this faint, when it creeps backinto the 14^th magnitude range its liable to provide an interestingsubject for visual observers who can pierce the haze from mid-northernlatitudes. This chapter of U Aqr is far from over and no one knows how thestory will develop from here.

The Boring

These are RCBs that for whatever reason just aren’t veryexciting to follow. They exhibit little, if any, activity and it has been yearsor decades since they showed any real sign of life at all.

SV Sge-

19 08 11.78 +17 37 41.2

Spec. type C0-3,2-3(R2)

Mag. Range 11.5 - 16.2 p

SV Sge since 1966

It wasn’t too long ago this star was a lot of fun to monitor.It seemed to be fading and recovering fairly often, bit the last time it didanything was 2004. I’ve grown tired of observing it at 10.5V for years on end,but I know better than to drop it, because that is the day it will go into atailspin and fade to record depths.

This is probably normal behavior for this star as the lightcurve above shows. I’m just impatient. It looks long overdue for a fade, butfor now it’s a yawner. When it finally does cough up a dust cloud I’ll take itoff the Bad list and put it back in the Good category.

MV Sgr

18 44 31.97 -20 57 12.9

Spec. type B2p(HDCe)

Mag. range 12 - 16.05 B

MV Sgr since 1987

With an amplitude of 1.5 magnitudes, this light curve looksa lot more like a semi-regular variable than an RCB. The spectrum is of ahydrogen deficient carbon star so it has the requisite color and composition,it just hasn’t done anything since we’ve been monitoring it. Twenty-five yearsisn’t long in the history of an RCB, so maybe we just need to keep an eye outfor activity. So far, it hasn’t been much fun.

V0482 Cyg

19 59 42.57 +33 59 27.9

Spec. type --

Mag. range 11.8 - <15.5 p

V482 Cyg 1967 topresent

The last fade was in 1996, three years before I startedobserving variables regularly. So in the time I’ve accumulated nearly 70,000observations, V482 Cyg has kept me waiting, based on the promise of a fade from11^th magnitude to 13.5 in the last century. If I wasn’t alreadyobserving dozens of stars in Cygnus I probably would have dropped it a longtime ago. All I can say is I hope the next fading event is worth waiting for,or my relationship with this bad star will suffer.

UV Cas

23 02 14.67 +59 36 36.6

Spec. type F0Ib-G5Ib

Mag. range 11.8 - 16.5 p

UV Cas since 1959

I remember a couple years ago some people got all excitedbecause this star had a half magnitude dip in its light curve, confirming whatI already thought about this star. It is one of the most R Cor Boring stars inthe sky. Apparently, a “deep fade” of two magnitudes 40 years ago is enough tokeep some observers monitoring this RCB. Not me, I dropped it long ago.

The Unknown

This category is made up of stars for which there are littleor no data in the AAVSO database. These stars are ripe for the picking. No oneelse is watching, you never know what you might find.

FH Sct

18 45 14.84 -09 25 36.1

Spec. type --

Mag. range 13.4 - 16.8 p

FH Sct from 2001 topresent

I knew next to nothing about this RCB when I added it to myCCD program in 2009. I soon discovered it resides in the open cluster M26 inScutum. There was no sequence for it when I began taking data, but now there isBVRI data available from the AAVSOnet telescopes and a color magnitude sequenceof comparison suitable stars has been created. In 2011 I caught the firstfading episode recorded in BVRI in the AAVSO database. Normally around 12^thmagnitude at maximum, it faded abruptly to 15V and has been steadily recoveringsince. There is no excuse not to observe this star now. It simply suffers fromneglect due to its southerly declination.

V1157 Sgr

19 10 11.83 -20 29 42.1

Spec. type C(R)

Mag. range 11.5 - <14.5 V

The epitome of an ugly light curve, the data for this staris sparse and unreliable. At -20 degrees declination, this one stretches thedefinition of a northern RCB to the limit, but any reliable data starting rightnow can only improve the situation here. Amplitude, maximum and minimummagnitudes, and pretty much everything else are uncertain for this RCB. My ownrecent observations only range from about 12 – 11.8V, not enough to sayanything for sure, except it is variable.

There is another “northern RCB” you may happen upon in theliterature, but LT Dra is not variable, it is a constant star, so don’t wasteyour precious telescope time following this one.

There are not that many observers following theseinteresting stars regularly, so the chance to hit upon something new orunexpected is always there. That coupled with their irregular and unpredictablenature makes them fun and challenging at the same time. Add a few of thesestars to your observing program and be prepared to be surprised.

Charles Butterworth Award

2011-10-09T07:08:00.002-04:00

Charles Butterworth was an early 20th century English amateur astronomer, and the first to accumulate 100,000 variable star observations. The British Astronomical Association's Variable Star Section has presented the Charles Butterworth Award twice, to individuals who have made an outstanding contribution to variable star astronomy.

Simostronomer and Gary Poyner

The first award was given to Arne Henden, Director of the AAVSO. I had the good fortune to be present at the joint meeting of the BAAVSS and the AAVSO in Cambridge, England in 2008, when my good friend, Gary Poyner was presented the second Charles Butterworth Award for surpassing the 200,000 variable star observation mark.

I was caught completely off guard when BAA representative, John Toone, after presenting a plaque and well wishes to the AAVSO from the BAAVSS, began speaking about the improvement in charts and sequences at the AAVSO Centennial Banquet. Before I realized where this was going he had announced that the BAAVSS had chosen to present me with the third Charles Butterworth Award.

The citation on the back reads, "This, the third Charles Butterworth Award, was presented to Mike Simonsen on 8th October 2011 by the Variable Star Section of the British Astronomical Association, in recognition of his outstanding contribution to the development of charts and sequences."

It is a beautiful hand etched and painted slate plaque whose face is a rendering of an AAVSO f scale chart of my favorite star, IW Andromedae, complete with comparison star labels. The stars are inlaid semi-precious stones that twinkle under light, and they are in precise agreement with both the position and brightness of the stars in that part of the sky.

I was left speechless at the sight of it, both for its beauty and the sentiment behind it from the people it came from. I shall treasure it always.

Congratulations, You've Been Elected!

2011-10-07T18:05:00.002-04:00

One of my dearest friends, Roger Kolman, was on the ballot for the AAVSO Council this year, but he did not have high hopes of being elected. "People just don't remember us old-timers anymore," Roger told me.

So when the results of the council elections were announced this morning at the AAVSO Membership meeting, I was excited that he had made it, and wanted to be the first to congratulate him. I quickly fired off an email on my Smartphone, entitled- "You've Been Elected!"

"Dear Roger,
You were 5th in line, but since one councilor went into the 2nd VP slot, they needed five out of eight, that's you!  Congratulations,  Mike"

About a half an hour later I received a reply:

"What? I wasn't aware I was up for election for anything! I certainly never put my name forward.  Cheers, Roger Pickard"

In my haste to notify my friend in Illinois that he had been elected, I had inadvertently sent the email to the Director of the British Astronomical Association's Variable Star Section! You can imagine his surprise in being told he now held another post as an AAVSO councilor.

I hastily wrote him another note apologizing for the confusion and assuring him he did not have to be at the next meeting in Big Bear, CA in May. He was quite relieved.

The AAVSO Traveling Star Party

2011-09-19T11:57:00.002-04:00

By now you’ve heard about several of us on the AAVSO staff traveling to various star parties throughout the US and Canada this year as part of our Centennial Celebrations. We’ve been meeting amateur astronomers and spreading the gospel and history of the AAVSO for nearly a year now.
My own personal experience has been that people from beginners to experienced astro-imagers are genuinely interested in variable stars and the AAVSO and they want to learn more. I’ve been invited back to give talks and run workshops at future star parties.

The other side of the personal experience has been meeting and talking with hundreds of amateur astronomers from around the country who share in the same passion for the night sky and understanding our place in the universe. I don’t care what anyone says, geeks are cool, and I’ve enjoyed hanging out with them under the stars as much as canoeing down the Niobrara River with them.

In an unrelated vein, some other activities I’ve been involved in this year have made me aware of Carolyn Hurless, the most prolific female observer in AAVSO history, and the star parties she held in Ohio, known notoriously as the “August Orgies”. I will be presenting a paper from Roger Kolman at the Friday evening Historical Session at the Centennial Meeting this fall about Carolyn and her astronomer friends, including Leslie Peltier, Clint Ford, Tom Cragg, Ed Oravec and Curtis Anderson.

It has also occurred to me, in my role as a planner of this fall’s centennial bash, that the social aspects of AAVSO meetings are every bit as important as the membership meeting and scientific paper sessions. All these isolated astronomers, used to sitting under the stars, or at the controls of their telescopes, in relative solitude, need a venue where they can get together and share their experiences with like-minded individuals who will understand what draws them to the night sky. Two times a year just isn’t often enough for these people to get relief!

Eventually, after swimming around in my head together for a while, these ideas started doing the backstroke together and a new idea began to surface.

Wouldn’t it be great if the AAVSO had a star party each year?!

It would be even more intimate and focused on the process of actually observing variable stars, and we would get all the social benefits of the star party experience. Old-timers could pass down their experiences to newcomers, participants could ogle each others gear and swap recipes, we could sit around the campfire on cloudy nights and share stories, and they would provide another opportunity to share science results in paper sessions during the day. Best of all, if we changed the location each year we could include more people from around the country by holding them closer to different populations of AAVSO members.

Then I thought, “Wait a minute, Mike. If this is as good an idea as you think, and everyone says let’s do it, you know who is going to have to do the work of organizing this thing, right?”

I’ve organized large star parties before for my astronomy club, and we have one each year at my place for 60-100 people, and it’s a LOT of work. I’m getting too old to continue adding things to my plate. No, there has to be a better way.

Then, while talking to someone about how well the Nebraska Star Party was organized, it dawned on me. We (meaningI) didn’t have to plan these parties. There is already a mechanism in place for that, the local organizers of these other star parties! They’ve already researched the locations, camping facilities, accommodations, catering, local weather and set up websites and registration processes. All we have to do is agree to which star party we are going to invade each year and show up with a bunch of VSOers. Everything else is already handled.

So I ran this up the flagpole at the last staff meeting, and got permission to go ahead with setting up the first one. All we needed to do was pick which star party we plan to invade this year.

Since we want to capitalize on the momentum we have going from the 2011 Centennial, we think it’s best to begin this right away. So we have decided to make the Winter Star Party, February 20-26, 2012, our First Annual Traveling AAVSO Star Party. What could be better than a trip to Florida in February?

Early registration begins in September and ends November 31st. Ticket prices go up after that. You can find out all about the WSP on their website.

Look for more information on the AAVSO Traveling Star Party soon on the AAVSO website.

Texas In My Rear View Mirror

2011-06-17T20:36:00.006-04:00

TSP or Bust

I couldn't have squeezed anything else in the car

As part of our program to introduce the AAVSO and our 100 year tradition to as many people as possible in 2011, we determined to send a speaker from the AAVSO to as many major star parties this year as we could. One of my assigned destinations in this mission was the Texas Star Party in Fort Davis, Texas. A couple days after returning from the joint AAVSO/AAS meeting in Boston, I was busy loading my 12” LX200 and all the necessary gear into my four-door sedan to drive the 1700 miles from my home in Michigan to the Davis Mountains in west Texas.

I left home Sunday morning, May 29. I ran into a ferocious storm just south of Chicago that forced me off the road and under cover to escape the wind, rain and golf-ball size hail pouring down from a black sky. The same storm hammered Battle Creek, MI, later that day, and places east the day after, as it tore a path across the upper Midwest and northeast. Other than that, the trip was largely uneventful, and I made good time.

The first night I stopped in Springfield, MO for the night. My original plan had been to push on to Joplin, but with the destruction from the tornado still dominating the headlines, I wasn’t sure there would be hotel rooms available for non-residents or non-relief workers. Monday night, I stayed in Midland, Texas, only a few hours away from Fort Davis. I just love Oklahoma and Texas, where the speed limit on the highway is often 80 mph. I could drive 94 mph without fear of getting a reckless driving ticket, and I did!

The entrance to the Prude Guest Ranch

I arrived in Fort Davis around 2pm on Tuesday. From there, it’s a short drive up highway 118, through some very pretty mountain terrain, to the Prude Guest Ranch, where the TSP is held.

My Big Texas Welcome
TSP is very well organized. I was greeted at the gate by organizers and shown where to check in at the office, where I picked up the key to a cabin I would be sharing with the other speakers. After unpacking, I claimed a spot on the middle observing field, right across the street from my cabin, and began to set up my telescope. On the advice of friends who had been to TSP before, I had purchased a tarp to cover the dusty ground around my scope and 10” spikes to nail it down with. They were not exaggerating at all when they told me I would need a three pound sledge hammer to drive the spikes into the rock-hard, red Texas dirt.

When it came time to heft the 12” LX200 onto the tripod, several guys who had been watching me set up in the mid-day Sun from their shade canopy under a large tree, ran over and offered to help. I soon learned they were veterans of many TSPs and claimed the same spot under this tree each year. In fact, they were now unofficially known as “The Shade Tree Gang”. I met a lot of warm, friendly, intelligent people at TSP, but the Shade Tree Gang were a lot of fun, and we spent a lot of time together.

The infamous Shade Tree Gang and Simochick

Don’t Call Me Late For Dinner
I was pretty hungry by the time dinner was being prepared in the mess hall at Prude Ranch. I decided to beat the rush and get in line early because I was feeling a little weak and light headed. Not knowing exactly where to go I headed inside the office, which led to the buffet line and salad bar attached to the dining hall. I sat down with a few other early birds and waited for the dinner bell. I think I might have drooled a little as they began bringing food out and stocking the salad bar.

After a while a back door to the building I did not know was there, suddenly opened and a line of people began streaming in. “This must be it!” I said to myself hungrily and walked over to the line, which led out the door, along the building, around a corner, up some steps and all the way to the door I had come in to wait for dinner in the wrong place.

I was one of the first people to show up for dinner, and now I was at the very end of a long line. I didn’t have enough energy, and I was too dehydrated, to cry.

Weathervanes

My little piece of Texas

At dinner that evening, I ran into my first fellow AAVSOer, Brad Walter. Brad and I had met before in Big Bear a couple years ago, but I didn’t recognize him right away with his safari gear and hat on. As it turned out, Brad was also camped on the middle field just yards from where my telescope was set up. After dinner I was finishing setting up for the night and began packing the tools and cases back into my car when Brad came over and told me I wasn’t done setting up yet. “What do you mean?” I asked him.
“Do you have any more of those spikes?”
“Yea.”
“You need to use them and some of that rope you have to tie down your telescope.”

Brad explained that even though my telescope was pretty darn heavy, the winds here in the Davis Mountains could be pretty fierce at times, and he advised me to tie down the three legs of the tripod to guard against the telescope blowing over!

He wasn’t kidding.

Clouds socked us in Tuesday night, and I decided to call it and get some sleep around midnight. Overnight, the star party was hit by, what could best be described as, a hurricane without the rain. Lightning flashed, thunder boomed and heavy winds, with violent gusts, shook the cabin until just before dawn.

When I walked out into the bright Texas sunlight Wednesday morning there were signs of destruction and chaos everywhere. Some of the smaller tents from the night before just weren’t there any more. Many shade canopies were dangling from ropes or wrapped around cars, and tent poles stood or lay on the ground with no canvas attached to them. You could tell which way the wind had come from because every Dobsonian telescope at the star party was facing in the opposite direction, having been turned in the night like a hundred weathervanes. And sadly, there were a few telescopes that had toppled in the storm.

Mine wasn’t one of them. It stood there unscathed, securely nailed to the ground. Brad had saved my telescope and my trip from disaster. I sent him a heart-felt thank you card the day after I got back from TSP.

Steve and Amelia Goldberg

I did some exploring around the star party that morning, took some pictures, found the free coffee at the vendors display and eventually made my way over to the meeting hall where I met with Bill Flanagan, the MC for the afternoon paper session, to load the PowerPoints for my two talks into the TSP computer. This is also where I met Steve and Amelia Goldberg, two of the organizers of TSP. They were great. Talk about your power couple. If I needed anything, or something with my room wasn’t just right, Steve would bark orders into a walkie-talkie and it would be handled, bam, now, no questions.

Spreading the Word
The talks after lunch were well attended. There were probably a hundred or more people in the hall. I gave condensed versions of two talks I have done before. Stand Back!, about citizen science projects in astronomy for amateurs, which of course features variable star projects, and Variable Stars and the Stories They Tell, which describes how variable stars fit into the larger landscape of astronomy and astrophysics using stellar evolution, the cosmic distance scale and the search for life in the Universe as examples.

Both talks were well received and followed by good Q&A sessions. TSP also awarded me a certificate of merit for each talk, which was yet another example of how they cross the tees and dot the I’s at this star party. If they could just control the weather…

After the talks, Tim Parson, from Minnesota, came up and introduced himself. I knew Tim from online, but we’d never met, so it was another chance to put a face to a fellow AAVSO observer who until now was just an email address. We talked about telescopes, cold weather observing, cataclysmic variables, star parties and got to know each other. I like Tim a lot.

Dinner Wednesday night was simply awesome. BBQ chicken, brisket and sausages, Pinto beans, potato salad, coleslaw, corn bread, cherry and apple cobblers; it was a feast. I sat with Tut Campbell of the CBA and learned all about his telescope farm and the observing he does. Tut is about as affable and friendly a guy as you’ll ever meet. He’s a passionate observer and I totally enjoyed listening to him talk while I gorged myself on barbecue. I also met Bill Pellerin, another active AAVSOer, who would be giving a talk on CCD observing Thursday afternoon.

Wednesday night the weather just teased us for a few hours. It looked like it might clear up, so I had my scope powered up, aligned and on standby, but the clear, dark Texas sky I drove 1700 miles to see never materialized. I finally forfeited at midnight. Texas Clouds 2, Visitors 0.

The only way to travel, a domed delivery truck on the upper field

Thursday was my big day. I was the scheduled speaker for the evening program, so I took it easy and treated myself to a light day. I slept in, went in to town for breakfast at a little diner that had wifi, to catch up on email and check the weather reports, then drove around the countryside and did some sightseeing. I also took a trip up the mountain to McDonald Observatory to gawk at the big telescopes under the silver domes. After lunch, I checked out the vendors’ displays to kill time before the afternoon paper sessions. Bill Pellerin gave a very good introduction to CCD observing talk, which featured variable stars, AAVSO and VPHOT.

Thursday, at dinner, I finally got to meet up with Walt Cooney, another AAVSO member. We had been playing phone tag, and missing each other since Tuesday when I arrived. After dinner I got called over to spend some time with Barbara Wilson, who would be hosting the evening program and introducing me. Barbara, a veteran of TSPs going back to the 80’s, is a legendary visual observer. She and her 20” telescope were featured in Timothy Ferris’ movie “Seeing In the Dark”.

When the time came, and Barbara handed the mic off to me, I found myself standing in front of 400 or so amateur astronomers who had made the pilgrimage to TSP from all around the country to share the dark skies and camaraderie of the Texas Star Party. Now they were sitting there expecting me to entertain and inform them for a while as we all waited for darkness to fall.

Barbara Wilson

When we had first discussed my coming to TSP, I explained to Barbara that I wanted to give a talk about the first 100 years of the AAVSO, since this was our centennial year. She was quite honest and said she didn’t think that would be very appealing to the TSP crowd, who were by and large deep sky hunters and aficionados like her. So I created a whole new program specifically for TSP. My talk was called The Unpredictable Deep Sky. It featured deep sky objects that changed their appearance on human time scales. As I’m sure you’ve guessed already, many of these changes are because they are associated with variable stars of one type or another.

The talk went well, it was just about the right length, the applause was enthusiastic, the Q&A was interesting but brief, and I felt a deep sense of relief as the crowd headed for the doors to go uncover their telescopes for what we all hoped would be a great night under the stars. I was on the down-slope now, my obligations having been met. I planned to coast through the next couple days and just enjoy the sky I had dragged my telescope 1700 miles to see.

Observing
The overcast sky didn’t offer much hope, and the glow from the wildfires burning just a few miles to the west of us extended up 30 degrees into the sky. These were the worst kind of clouds. They’d thunder and lightning and spoil the night sky but the didn’t give up a drop of rain. This part of the country was parched. It hadn’t rained here since September.

I refused to give up and hung out and talked and laughed with the Shade Tree Gang until well past midnight, hoping for a miracle. What we got was about half a miracle. The sky above us and to the south and east did clear up around 1:30am so we were actually able to observe for about three hours until just before dawn began to break. It wasn’t the incredible life changing experience I had hoped for. In fact, it’s that dark at my house on a good moonless night. But I was able to look through some other telescopes, try some new eyepieces and share the views of a few galaxies, nebulae and clusters in my 12” proudly.

I was very impressed with Keith Venables’ portable 10” telescope, which breaks down to fit inside a gun case. He had it hooked up to an application running on an IPad that showed its location very accurately. So accurately, in fact, that he was able to locate several parts of the Veil nebula he had never seen before using it to guide him.

The optics of his compact Dob were first rate, and I got my first look through a couple of Ethos eyepieces. I couldn’t get over how flat the field looked and how positively comfortable the eye relief and general feel of the Ethos was. I tried them in my LX200 and felt the same way, although it wasn’t as noticeable an improvement over the Naglers I normally use as I thought it would be. Still, I can see one or two of these fine eyepieces ending up in my kit eventually.

At last, it finally felt like a star party. Tim Parson observed with me and we had fun comparing notes and just being around telescopes under the stars. Some people wandered by and we’d show them what ever we were looking at. It wasn’t a big score, but it wasn’t a defeat. I’d call it a scoreless tie. The Texas Clouds had not swept me. But I was still losing the series 2.5 to 0.5. The best I could do was tie, and it would have to be clear Friday and Saturday, which would mean I’d have to stay Saturday, instead of driving home, which was Plan A.

Let’s Make A Deal
Friday morning I hurried into town to get breakfast and log on to the free wifi. TSP had wifi, but it wasn’t working very well, so this was the best way to get Internet access, check email and most important of all, check the weather. It was also the only time I could get phone reception, so checking in back home became part of the morning routine. But I had to rush through all that today, because at 9am was the swap meet outside the vendors building, and I had brought a box full of gear I never use any more to sell or trade.

I arrived back at the ranch just as the swap meet was getting underway. I pulled my box of goods out of the trunk and set up shop in amongst the other hopefuls who had brought merchandise to sell or trade. I was in the mood to deal. I didn’t want to bring any of this stuff back home with me, and I had already purchased a new observing chair I had seen at one of the vendor displays. I needed to recoup my investment. I was a motivated seller and did very well. I sold everything, even the box!

The Lost Weekend
Friday lunch was actually brunch. They served eggs, biscuits and gravy, French toast, corned beef hash, bacon, sausage, hash browns, fruit and cereal. The weather may have sucked to this point, but the food was outstanding! After lunch they herded us all out on to the burnt lawn outside the dining hall for the traditional TSP group picture. They arranged us and handed out letters that spelled Texas Star Party 2011. I took a long nap that afternoon and wrote some notes about the trip to use in any blogs or articles I was planning to write. The weather report was not looking very good again and I started mentally packing.

After dinner Friday, Brad Walter and I sat down together for a while and he showed me some interesting projects he was working on in his spare time. One was a graph of the ASAS V magnitudes versus Landolt standards, which seemed to indicate ASAS V mags are pretty robust from 7th to 14th magnitude. I encouraged him to finish this work and have it published before the AAVSO All Sky Survey makes it obsolete! He also had a great idea for a variable star science website which I won’t describe here. Hanging out with brilliant people is one of the side benefits of going to astronomy conferences, meetings and star parties.

Friday night was cloudy, so after the evening program, a talk given by C. Renee James about her new book, Seven Wonders of the Universe You Probably Took for Granted, we spent it socializing and partying. I read some of the funny stories from my blog to the guys and we shared our own stories of observing, traveling, star parties, and other misadventures. Sometime during the night I began thinking I’d come too far to give up and I was going to stay Saturday if the weather forecast looked at all promising.

Saturday morning over breakfast I decided I was going to stay for the last day, just in case the weather broke. I had concluded that even though the weather forecast was questionable at best, I would be sick if I packed up and drove away from TSP just as the skies cleared over the Davis Mountains. I called home and told Irene I was going for ‘Plan B’.

I also told her I’d be taking a different route home. One of the guys I’d become friends with was Art Smoot, an airline pilot from Dallas. He suggested I take a route through Texas west and then north instead of the way I came, to avoid the two lane blacktop roads I’d taken through northern Texas on the way down. I figured if there was anyone to listen to when it comes to getting from point A to point B it’s an airline pilot.

Saturday afternoon featured another paper session. Keith Venables, one of the Shade Tree Gang, was giving a couple talks and I looked forward to hearing them. The first was an overview of all the telescopes he’d ever owned and what was right or wrong with them, called Equipment: How Much Is Enough? It was very clever and explained the evolution of his lightweight Dob that fit in a gun case. He is from the UK, and when airline restrictions on luggage and carry-ons were tightened after 911, he had to adjust his travel scope accordingly. He also gave an interesting talk about his attempts at finishing an entire Messier Marathon from different locations around the world.

Dinner that evening was rib-eye steak, baked potatoes, veggies, rolls and salad bar. I know I’ve mentioned the food a lot in this piece, but the food at the Prude Guest Ranch is really quite good. With cloudy skies at night and hot dusty days, the food was one of the highlights of the trip.

William Keel, from the University of Alabama, was the featured guest speaker Saturday night. He gave an excellent, if lengthy, talk on Citizen Science, featuring Galaxy Zoo, Hubble Zoo, Moon Zoo and other parts of the Zooniverse.

The weather hadn’t improved at all. In fact, it started raining suddenly after dinner so I had to run back to my site to get things out of the rain. I got soaked doing it and had to change, so I missed the first part of Bill’s talk that night.

I finally had to admit defeat and began packing things away that night, as best I could in the dark. Texas Clouds 4.5, Visitors 0.5.

Sunday morning I was ready to pack up and hit the road. Observing had been a bust, but I’d had a good time anyway. I met people I only knew through email and made some new friends. I vowed not to let Texas clouds beat me, so I will be back one day, maybe next year.

No Place Like Home
It took all day Sunday to drive across Texas from west to east. I stopped in Little Rock, Arkansas overnight then drove like a man possessed Monday to get home in one long push. I think the police in Indiana are still looking for me. I pulled into my driveway around 1:30am Tuesday morning where- you guessed it-- the Milky Way shone down on me from a clear, moonless sky.

Scorpio to Lose Status as Zodiac Sign

2011-05-24T07:48:00.002-04:00

The biggest buzz coming out of the 218th Annual Meeting of the American Astronomical Society in Boston on Monday, centered around a plan to remove the constellation Scorpius from the Zodiac and replace it with the constellation Ophiuchus.

"We're mostly concerned with science and the facts, but astrology is just a mess, and this might help with astrologers predictions", says Dr. George VanDelay, author of the proposal, with more than a hint of sarcasm.

What precipitated this controversial shift in policy is the fact that the Sun actually travels through thirteen constellations as seen from the Earth on its annual trip around our nearest star. These are the twelve traditional zodiac constellations and Ophiuchus. "We tried to get the thirteenth sign, Ophiuchus, officially recognized as a zodiacal sign a few years ago, but the traditionalists insisted on keeping a dozen only", VanDelay explained. "The problem is the Sun is in the constellation Scorpius for less than a week, while it resides in Ophiuchus for almost three weeks out of the year."

The red dashed line is the Sun's path through Scorpius and Ophiuchus

In a surprise move, VanDelay announced a new, more radical proposal to take to the International Astronomical Union, the official body who names celestial objects and determines the boundaries of constellations. His solution is to adjust the constellation boundary between Scorpius and Ophiuchus to re-assign the section of Scorpius that the Sun travels through for 6 days each year into the constellation of Ophiuchus.

The crowd of astronomers in the main Westin Hotel conference room reacted angrily at first. "Most astronomers prefer the solution we came up with before; adding Ophiuchus to the Zodiac. That represents the more scientific approach to this ages old problem. There are already millions of people who have adopted Ophiuchus as their Sun sign", said Dr. Ken Marvelous of the AAS. "But, VanDelay makes a lot of sense. We just have to make sure the IAU doesn't try to demote Scorpius to 'dwarf constellation' status with this redrawing of the boundaries."

"We tried to reason with astrologers on this Ophiuchus issue before", said VanDelay. "Now it seems the best way to resolve the whole thing forever, is to just eliminate Scorpius from the equation." By the time VanDelay was done laying out his plan to take a constellation reorganization plan to the IAU, the crowd was energized and gave him a standing ovation. It seems almost certain the AAS will endorse this restructuring of the zodiac. This kind of proposal usually takes a couple years to make it through the IAU submissions process, but VanDelay has already quietly submitted a written proposal, so this will be on the agenda at the next IAU General Assembly in Beijing, August 20-31, 2012.

"This is a brilliant plan", said Dr. Wilson Hale of UC Berkeley, "They already cut off the Scorpion's claws ages ago to create the constellation Libra. That just shows how arbitrary this whole thing is."

Angelica Spock from University of Missouri added, "It's no secret that astrological predictions have never been less reliable that they are today. My horoscope is almost never right any more. Maybe this will help astrologers get their act together."

Let the Astro-Traveling Begin!

2011-04-03T10:46:00.003-04:00

As I mentioned in my post about speeding across New York last month, this summer and fall are going to be a very busy time filled with lots of astronomy related travel for the Simostronomer.

It starts in April, when Irene and I will be driving to Suffern, New York, for the Northeast Astro-Imaging Conference (NEAIC) and Northeast Astronomy Forum (NEAF). Both of these events are hosted by the Rockland Astronomy Club, one of the country's most active and prestigious astronomy clubs. For example, their newsletter, Distant Light, looks like a professional astronomy magazine. Their membership includes people like Jim Burnell and Al Nagler. NEAF is the east coast's major show for astronomy vendors. I gave a workshop there last year on variable star observing, and my first experience with NEAF was a mind-blower. It's a great event. if you ever get a chance to go, do so. NEAIC is held immediately before NEAF, and its more of a high end astro-imaging orgy for guys with sophisticated rigs and observatories, and those considering taking the plunge into this ever-growing segment of amateur astronomy. I'll be giving a talk at NEAIC about using your CCD for science, called "Stand back! We're Going To Try Science." My tip of the hat to the xkcd website and their T-shirt with the same saying.

Then in May, I'll be flying to Boston for the joint AAS/AAVSO meeting, celebrating our 100 years as an astronomical organization in America. This meeting will begin around noon on Saturday, May 21, with an afternoon AAVSO Paper Session followed by the AAVSO banquet that evening. Sunday will feature a morning AAVSO Paper Session, and an afternoon joint session with the AAS Historical Astronomy Division (HAD). Sunday evening, we'll host the AAS Welcome Reception. Monday will include two topical plenary talks on variable star science as well as 2 AAVSO-sponsored, variable star special sessions, "Astrophysics With Small Telescopes" and "Variable Stars in the Imaging Era" and an evening open house at AAVSO HQ. I'll be presenting a poster about the AAVSO robotic telescope network at the AAVSO sessions, and I'm giving a talk on my Z Cam research at the "Astrophysics With Small Telescopes" session.

Two days after I get home from Boston, I'll be packing up the car and driving to the Texas Star Party in Fort Davis, Texas. I've never been to the TSP before, so this is something I'm looking forward to very much. I'm taking my telescope and plan to take advantage of some of the darkest skies in North America at this event. I am also giving one of the evening featured talks, and some short papers in the afternoon. I'm also looking forward to a tour of McDonald Observatory, just up the road from TSP.

In July, its back to AAVSO headquarters for meetings and planning sessions. We should be in full blown craziness getting ready for the Fall 2011 AAVSO meeting about then as well as putting the finishing touches on several large grant proposals that are due around that time.

The last weekend in July, Irene and I will load up the camping gear and head for Nebraska for the Nebraska Star Party, August 1-5. This is also one of the big annual star parties held in a remote dark sky site. Another first for me, I'm really looking forward to this, and the telescope and gear will be making this trip too. This star party is held on the Merrit Reservoir, which was created by damming the Snake River. There's lots to do and see during the day. I'm particularly looking forward to a canoe trip down the Niobrara River. The Niobrara is rated one of the top ten canoeing rivers in the country. "Steep canyons rimmed with birch, oak, and pine trees frame the river in spectacular beauty", according to the travel guide. I'll be doing a talk on deep sky objects and variable stars, similar to the one I'll be giving in Texas in June.

I make one last solo trip to Boston in September to put the final plans in place for the October meeting.

Then, in October is the Big One, the AAVSO Fall 2011 Centennial Celebration in Woburn, MA. The AAVSO's 100th birthday is going to be a party. This is going to be the biggest AAVSO meeting in history, with special events, a dinner cruise on Boston harbor, historical and future looking papers and attendees from around the world. Mrs. Simostronomer will even be making a rare appearance at this AAVSO meeting!

We'll be staying home after that, but I have a feeling we might go someplace warm next winter for a while, and we won't be taking a telescope. I'll be completely out of spousal permission units by then.

Second Thoughts On A New AAVSO Logo

2011-03-21T07:17:00.000-04:00

I had just made a quick pit stop along the New York throughway and was back on the road again heading east towards Boston. The weather was pretty decent for March, and I had been consistently pushing or exceeding 80 mph most of the way through New York taking advantage of the partly sunny, dry day.

Keenly aware that I was doing 15 mph over the speed limit most of the time, my eyes were peeled and on the lookout for state police hiding in the median or on the side of the highway far down the road ahead. I had dodged being detected a few times already by noticing ‘the boys’ hiding in strategic positions, ready to pounce on the unsuspecting speeders who would be filling the coffers of the state with their traffic fines this day, and I’d felt pretty smug each time I saw the flashing lights in my rear view mirror as some driver lacking my keen instincts was pulled to the side of the road in highway humiliation.

I was making great time, and it looked like I would be pulling into the parking lot at AAVSO headquarters about an hour earlier than I expected. That’s when I saw him.

Apparently, I hadn’t noticed the traffic behind me parting like the Red Sea as ‘Smoky’ raced to catch me from behind. He was now even with me in the left lane, looking right at me, or was it something else? He seemed to be looking behind me, like I had a broken rear window or something. Then he looked right at me, then behind me. I was already decelerating, expecting the flashing lights to come on at any minute when the strangest thing happened. He tipped his hat and took off down the road at what seemed to be 100 mph.

It wasn’t until I stopped for gas a few hundred miles later, and looked in my window as I filled up, that it dawned on me what had happened. There in my rear driver’s side window was my AAVSO decal. I have one in the passenger side window too. I display them with pride. I have to admit, though, I have been a proponent of a new logo for many years. My main objection being the current logo looks too stiff and old-fashioned, and too similar to the many sheriff’s department logos across this great country of ours. It doesn’t scream out “astronomy”. At first glance, it says “police”.

I think that AAVSO police decal in my window may have saved me a fine, points on my driving record, an increase in insurance premiums and a long string of disapproving ‘wife looks’ for the next month or so. Maybe it’s old-fashioned, but I kind of like that sheriff’s star logo now. I have a lot of driving to do this year, NEAIC in New York, Boston a few more times, the Texas and Nebraska Star Parties. Yea, those AAVSO decals are staying in my windows for the foreseeable future. Long live the AAVSO star.

Variable Star Chart Obsession

2011-03-05T10:18:00.000-05:00

Every few years or so, the dining room table in my house becomes “AAVSO Variable Star Charts Central”. The centerpiece, placemats and silverware are put away, and in their place are three ring binders, plastic page protectors and stacks of paper charts. The printer in my office gets a workout, and I become a regular at the office supply store, buying ink, paper and other supplies as the project progresses.

This is the fifth time in ten years I have performed this major renovation project, so I’ve got it down to a science now. I’ve kept most of the charts that have been replaced, so it has become a sort of archival history project too.

When I first started observing, I started with all the stars in David Levy’s book A Guide to Variable Stars. I used everything I could lay my hands on. Old "micro-dot" charts, preliminary charts, and a few new format charts that I would have to hold upside-down and shine a flashlight through to match the view in the eyepiece. In 1998, not everything in the chart catalog was online yet, and only a small percentage of the charts were available as reversed charts for use with a Schmidt-Cassegrain. It wasn’t long before my observing program became all the stars with available reverse charts. That was a lot easier than using the flashlight trick or trying to flip them in your head.

I realized immediately that I would need to organize all these charts into binders to keep them protected from the dew, frost, and wind. My system evolved quickly, and it hasn’t changed much over the years. I printed wide field finder charts from planetarium software with a limiting magnitude of about 9 that had a circle indicating the size of my finder scope field of view, and a little arrow pointing to my ‘jumping off star’. This was the star I would aim for when dialing in the setting circles or star-hopping to the next target. The same star would be indicated on the variable star chart so when I got to the eyepiece I could find my way to the variable star by star-hopping from there.

In the binder, the finder chart was on the left and the variable star chart on the right. Simple for most CVs, I usually only needed one comparison chart. Each time I flip the page I'm on a new star. Mira stars with large amplitudes usually require additional charts. Typically, B charts for maxima above 9th mag, which I observe using the finder scope, D charts for 10-13th mag and E charts for fainter than 13th mag or to relieve crowding on some D charts. Some Milky Way fields require F charts to relieve the crowding of comp star labels or to show 15th magnitude comps.

The second generation of charts began with me printing reversed star fields from planetarium software and hand labeling the magnitudes, but I always hated the messy look of my handwriting on these charts and they were limited by the contents of the Guide Star Catalog, so they didn’t last long. Once the complete AAVSO chart catalog became available online, I started downloading all the charts and flipping the fields and labels around in an art program. I think that was when the true chart madness set in. I couldn't decide what to observe, so I decided to observe everything! I made hundreds and hundreds of charts in various scales and orientations.

My CV binders stayed more or less unchanged for a long time once I had maximized the order for speed. That was an interesting project. I took day-glow stickers and labeled them with the names of all my CVs then placed them on their respective pages of Sky Atlas 2000 so I could figure out the most efficient order to observe them in. I recently read a paper on ACP Scheduler and was pleased to see I had followed the same logic as the software in assigning the observing order. I just did it the old-fashioned analog way. The same way I was observing.

Using those binders I was able to observe 100+ CVs on a decent night. I did over 250 in a night a few times. It’s easy when all you are doing is reporting, “it isn’t in outburst”. But I have to admit 250 is just insane.

In 2003, I began coordinating chart production at AAVSO and we started the last major overhaul of the chart catalog before VSP came online. By 2005, I had replaced all my previous charts with the new ones we were making using Henden and ASAS photometry. Until recently, I still preferred these charts to anything the chart plotter could produce. They were beautifully crafted, hand labeled and thoroughly checked before being released to the public. But there was no way we could continue that practice and keep up with the pace of new discoveries or the demand for more and better charts.

By 2009, we had revised a significant percentage of the sequences with newer, better photometry and it was time to bring the binders back indoors from the observatory for another update. Not only that, but now I had a CCD on another telescope in a new roll off and I needed a whole different set of charts for those program stars!

With the latest round of improvements to VSP most of my previous objections to the charts it produces have been eliminated. First among these were the ridiculous huge star dots it used to plot for many variables! I have hated those blobs for years. So here we are again, updating all the chart binders and revising the observing programs again.

My visual program is now going to concentrate on AAVSO Legacy and Program LPVs. I want to observe stars I can make positive estimates of 99% of the time. I have tens of thousands of “fainter than” observations in the AID and I don’t find them that much fun to make any more. So I have several binders with all new LPV charts for the eyepiece.

My CV program will just be the prototypes, legacy CVs, bright active stars and a few favorites I will observe forever just because I like them. I’m pretty sure I will never sit out all night under the stars and report “I didn’t see it” 100 times ever again. Let someone else discover the next outburst of PQ And. I want to make observations you can plot on a light curve.

I have another binder for the CCD scope. That program is Z CamPaign stars, northern RCB, recurrent novae and some quirky favorites. I affectionately call them my ‘oddball' program stars.

Well, time to go. The printer has grown quiet, so I either have another batch of charts to organize, or I’m out of paper. Until next time…

Frozen Fog

2011-02-07T09:24:00.000-05:00

I got an email from a friend in Australia this morning describing a problem with weather at the New Mexico site where his robotic telescope is housed. Along with record cold temperatures, he said locals described "snow coming out of a cloudless sky". Living and observing from the frozen tundra of Michigan, I knew instantly what he was referring to. It's called frozen fog. The last time I'd seen it was in 2004. At the time, I wrote about it to the AAVSO Discussion List.

Just after midnight this morning I had to close the dome, in spite of the
fact there wasn't a cloud in the sky and virtually no wind. The culprit:
frozen fog.

When the humidity approaches 100% and the temperature and conditions are
just right, the sky begins to snow without the presence of clouds. It always
catches me by surprise because I just don't expect snow when there isn't a
cloud in the sky! It's a pain for astronomy, but it is every bit as
beautiful as the northern lights.

Frozen fog doesn't fall really, it just appears and then gently settles on
things. You can literally watch it form before your eyes. Like magic, it
just comes out of nowhere. It has a very sticky nature, so it tends to stick
to everything it touches; trees, bushes, houses, hats, gloves...

Watching it precipitate under the icy blue glow of a full moon was quite a
treat. I held my hand up in front of the moon and watched frozen fog turn my
glove into a pure white, flaky decoration bathed in moonlight that looked
good enough to eat.

When the sun comes up the landscape has been transformed into a wintry
paradise, sprinkled with pure white, glistening fairy dust. Most people get
up and assume it snowed last night, but I know better. It's magic...frozen
fog.

Solving the Mystery of Dark Gamma Ray Bursts

2010-12-17T13:41:00.000-05:00

Artists impression of a dark gamma-ray burst. Credit: ESO

Unraveling the mystery of Gamma Ray Bursts (GRBs) is a story filled with international intrigue, fantastic claims, serious back-tracking, and incremental improvements in our understanding of the true nature and implications of the most energetic, destructive forces in the Universe. New results from a team of scientists studying so-called “dark gamma-ray bursts” have firmly snapped a new piece into the GRB puzzle. This research is presented in a paper to appear in the journal Astronomy & Astrophysics on December 16, 2010.

The discovery of GRBs was an unexpected result of the American space program and the military keeping tabs on the Russians to verify compliance with a cold war nuclear test ban treaty. In order to be sure the Russians weren’t detonating nuclear weapons on the far side of the Moon, the 1960’s era Vela spacecraft were equipped with gamma ray detectors. The Moon might shield the obvious signature of x-rays from the far side, but gamma rays would penetrate right through the Moon and would be detectible by the Vela satellites.

By 1965, it became apparent that events which triggered the detectors but were clearly not signatures of nuclear detonations, so they were carefully, and secretly, filed away for future study. In 1972, astronomers were able to deduce the directions to the events with sufficient accuracy to rule out the Sun and Earth as sources. They came to the conclusion that these gamma-ray events were "of cosmic origin". In 1973, this discovery was announced in the Astrophysical Journal.

This created quite stir in the astronomical community and dozens of papers on GRBs and their causes began appearing in the literature. Initially, most hypothesized the origin of these events came from within our own galaxy. Progress was painfully slow until the 1991 launch of the Compton Gamma Ray Observatory. This satellite provided crucial data indicating that the distribution of GRBs is not biased towards any particular direction in space, such as toward the galactic plane or the center of the Milky Way Galaxy. GRBs came from everywhere all around us. They are "cosmic" in origin. This was a big step in the right direction, but created more questions.

For decades, astronomers searched for a counterpart, any astronomical object coincident with a recently observed burst. But the lack of precision in the location of GRBs by the instruments of the day frustrated attempts to pin down the sources of these cosmic explosions. In 1997, BeppoSAX detected a GRB in x-rays shortly after an event and the optical after glow was detected 20 hours later by the William Herschel Telescope. Deep imaging was able to identify a faint, distant galaxy as the host of the GRB. Within a year the argument over the distances to GRBs was over. GRBs occur in extremely distant galaxies. Their association with supernovae and the deaths of very massive stars also gave clues to the nature of the systems that produce GRBs.

It wasn’t too long before the race to identify optical afterglows of GRBs heated up and new satellites helped pinpoint the locations of these after glows and their host galaxies. The Swift satellite, launched in 2004, is equipped with a very sensitive gamma ray detector as well as X-ray and optical telescopes, which can be rapidly slewed to observe afterglow emissions automatically following a burst, as well as send notification to a network of telescopes on the ground for quick follow up observations.

Today, astronomers recognize two classifications of GRBs, long duration events and short duration events. Short gamma-ray bursts are likely due to merging neutron stars and not associated with supernovae. Long-duration gamma-ray bursts (GRBs) are critical in understanding the physics of GRB explosions, the impact of GRBs on their surroundings, as well as the implications of GRBs on early star formation and the history and fate of the Universe.

While X-ray afterglows are usually detected for each GRB, some still refused to give up their optical afterglow. Originally, those GRBs with X-ray but without optical afterglows were coined “dark GRBs”. The definition of "dark gamma-ray burst” has been refined, by adding a time and brightness limit, and by calculating the total output of energy of the GRB.

This lack of an optical signature could have several origins. The afterglow could have an intrinsically low luminosity. In other words, there may just be bright GRBs and faint ones. Or the optical energy could be strongly absorbed by intervening material, either locally around the GRB or along the line-of-sight through the host galaxy. Another possibility is that the light could be at such a high redshift that blanketing and absorption by the intergalactic medium would prohibit detection in the R band frequently used to make these detections.

In the new study, astronomers combined Swift data with new observations made using GROND, a dedicated GRB follow-up instrument attached to the 2.2-metre MPG/ESO telescope at La Silla in Chile. GROND is an exceptional tool for the study of GRB afterglows. It can observe a burst within minutes of an alert coming from Swift, and it has the ability to observe through seven filters simultaneously, covering the visible and near-infrared parts of the spectrum.

By combining GROND data taken through these seven filters with Swift observations, astronomers were able to accurately determine the amount of light emitted by the afterglow at widely differing wavelengths, all the way from high energy X-rays to the near-infrared. They then used this data to directly measure the amount of obscuring dust between the GRB and observers on Earth. Thankfully, the team has found that dark GRBs don’t require exotic explanations.

What they found is that a significant proportion of bursts are dimmed to about 60–80 percent of their original intensity by obscuring dust. This effect is exaggerated for the very distant bursts, letting the observer see only 30–50 percent of the light. By proving this to be so, these astronomers have conclusively solved the puzzle of the missing optical afterglows. Dark gamma-ray bursts are simply those that have had their visible light completely stripped away before it reaches us.

How Old is the Universe?

2010-12-12T18:13:00.001-05:00

This could be the shortest book review ever.
I absolutely love this book- buy it!

I'm serious. I enjoyed reading this book more than anything I have read in a long, long time. I liked everything about it.

David A. Weintraub tells the story of how we know what we know about the universe from the beginning to the end in a simple, elegant, chronological manner. By doing this, you see how each new discovery builds on the knowledge gained by the previous generation of scientists working on the fundamental questions about the universe.

Two things impressed me most. First, the way each discovery is framed in a historical context made it clear how answering each new question fit into the overall picture. It is as much a history of astronomy as it is an explanation of how we know what we know today. Because you see the story unfold in this way, and witness scientists using each new clue to solve another puzzle, the book reads like a great mystery novel. It is one of the most entertaining books you'll ever read on astronomy.

Second, the author writes about serious astrophysical concepts in a clear, honest, readable tone accessible to everyone. You don't need to be an astronomer or physicist to understand what Weintraub is explaining. For example, the 100 words or so he uses to explain black body radiation and why it is an important concept are so well written that I feel I have a better understanding of something I thought I already understood. Disntangling the Hubble constant, the Hubble equation and Hubble time is something that has never been explained as well as it is in this book. I never understood why William Herschel was so interested in double stars until I read this book. It's not a complicated subject, it's just never been presented to me in the context it is in this book. I totally get it. Thank you, David.

I had at least a half dozen epiphanies reading this book. I didn't just learn new facts or concepts, I truly understand some things better than I ever did before. 'How Old Is The Universe' is my new favorite astronomy book. I plan to read it again.

A Comet Masquerading as an Asteroid

2010-12-12T14:24:00.002-05:00

596 Scheila, the asteroid with a tail. Image credit: Peter Lake

When is an asteroid not an asteroid? When it turns out to be a comet, of course. Has this ever happened before? Why, yes it has. In fact it was just announced December 12, 2010 that the asteroid (596) Scheila has sprouted a tail and coma!

Steve Larson of the Lunar and Planetary Laboratory (LPL), University of Arizona first reported that images of the minor planet (596) Scheila taken on December 11th showed the object to be in outburst, with a comet-like appearance and an increase in brightness from magnitude 14.5 to 13.4. The cometary appearance of the object was confirmed be several other observers within hours.

A quick check of archived Catalina images of Scheila from October 18, November 2 and November 11 showed Sheila to look star-like, which is what asteroids look like from Earth. They just happen to be moving across the field of view in contrast to the fixed background stars. The image taken by Catalina on December 3rd shows some slight diffuseness and an increase in overall brightness. So, it appears this event began on or around December 3rd.

Upon hearing the news, there was some speculation that this might be evidence of an impact event. Had something crashed into asteroid Scheila? It seems unlikely, and this is a story we have heard before.

The asteroid discovered in 1979 and named 1979 OW7 was lost to astronomers for years and then recovered in 1996. It was subsequently renamed 1996 N2. That same year it was discovered to have a comet-like appearance, and many believed this was the signature of an impact between two asteroids. After years of inactivity 1996 N2 sprouted a tail again in 2002. One collision between two asteroids was unlikely enough. The odds of it happening again to the same object were essentially zero. What we had was a comet masquerading as an asteroid. This object is now known by its cometary name 133P/Elst-Pizarro, named after the two astronomers who discovered its initial cometary outburst.

The 2002 outburst and the discovery of more active asteroids showing mass-loss led to a paper (Hsieh and Jewitt 2006, Science, 312, 561-563) introducing an entirely new class of solar system objects, Main Belt Comets (MBC). MBCs look like comets because they show comae and have tails but they have orbits inside Jupiter's orbit like main belt asteroids.

The most likely cause of the mass loss activity in MBCs is sublimation of water ice as the surface of the MBC is heated by the Sun. This is suggested most strongly by the behavior of the best-studied example, namely 133P/Elst-Pizarro. Its activity is recurrent, and it is strongest near and after perihelion, the point in its orbit nearest the Sun, like other comets.

MBCs are interesting to astronomers because they appear to be a third reservoir of comets in our solar system, distinct from the Oort cloud and Kuiper belt. Since we know of no way for theses other reservoirs to have deposited comets in the inner solar system, the ice in MBCs probably has a different history than the ice in the outer comets. This allows researchers to study the differences in the Sun’s proto-planetary disk at three separate locations. This might lead to information on the Earth’s oceans, one of the continuing lines of investigation by solar system scientists.

Now it seems we have another MBC to add to the sample. And Scheila will probably be getting a new name soon. Asteroid (596) Scheila was discovered Feb. 21, 1906, by A. Kopff at Heidelberg. The 113Km in diameter ‘asteroid’ was named after an acquaintance, an English student at Heidelberg. In the future it will be called XXXP/Lawson or something similar, and Kopff’s Sheila will become just another footnote in the history of astronomical nomenclature.

Venus Has a Moon?

2010-12-09T10:49:00.000-05:00

Venusian quasi-satellite 2002 VE68
Illustration: NASA/JPL/Caltech

Astronomers have been busy trying to determine the spin period and composition of Venus' moon. December 8, 2010, results were announced by JPL/Caltech scientists, led by Michael Hicks.

"Wait a minute; back up", I hear you ask. "Venus has a Moon?"
Of course it does. Well, kind of...
Let me explain.

It has the rather unfortunate name of 2002 VE68. That is because it was discovered on November 11, 2002 by LONEOS, the Lowell Observatory Near Earth Object Search. 2002 VE68 is an earth orbit -crossing asteroid that has been designated a Potential Hazardous Asteroid by the Minor Planet Center. For obvious reasons, this makes it a very interesting subject of study for JPL scientists.

2002 VE68 used to be a run of the mill, potential impact threat, Near Earth Object. But approximately 7000 years ago it had a close encounter with Earth that kicked it into a new orbit. It now occupies a place in orbit around the Sun where at its closest it wanders inside the orbit of Mercury and at its furthest it reaches just outside the orbit of the Earth. It is now in a 1:1 orbital resonance with Venus.

An orbital resonance is when two orbiting bodies exert a regular, periodic gravitational influence on each other due to their orbital periods being related by a ratio of two small numbers. For example, Pluto and Neptune are in an orbital resonance of 2:3, which simply means for every two times Pluto goes around the Sun, Neptune makes three trips around.

In the case of Venus and 2002 VE68, they both take the same time to orbit the Sun once. They are in a 1:1 orbital resonance. So by definition, 2002 VE68 is considered a quasi-satellite of Venus. If you watch the Orbital Viewer applet at the JPL small body page you can watch this celestial dance as the two bodies orbit the Sun and each other as 2002 VE68 dodges Earth and Mercury in the process.

Often these resonances result in an unstable interaction, in which the bodies exchange momentum and shift orbits until the resonance no longer exists. In this case, scientists believe 2002 VE68 will only remain a Venusian quasi-satellite for another 500 years or so.

So getting back to the story, Hicks and his team used the recent close apparition of 2002 VE68 to do photometric measurements over the course of three nights in November using the JPL Table Mountain 0.6m telescope near Wrightwood, California. From the color data they obtained they determined that 2002 VE68 is an X type asteroid. This is a group of asteroids with very similar spectra that could potentially have a variety of compositions. They are further broken down into Tholen classification types as either E, M or P types. Unfortunately Hicks' team was not able to resolve the sub-classification with their equipment.

They were able to determine the approximate size of the asteroid to be 200 meters in diameter, based on its absolute magnitude, and they determined a spin rate of 13.5 hours. The amplitude of the fluctuation on the light curve of 2002 VE68 could imply hat it is actually a contact binary, two clumps of asteroidal material orbiting a center of mass in contact with each other.

For more information on some of the strange and curious beasts in the asteroidal zoo, visit the NASA Near Earth Object Program website.

100 Years of Citizen Science

2010-11-29T17:36:00.001-05:00

On October 10, 2011, the American Association of Variable Star Observers (AAVSO) will turn 100 years old. To celebrate One Hundred Years of Citizen Science, we have planned grass roots outreach, website features, observing challenges and two meetings to commemorate this historic occasion.

So what is the AAVSO, and what is all the fuss about?

The AAVSO is a worldwide, non-profit, scientific and educational organization of amateur and professional astronomers who are interested in stars that change in brightness—variable stars. Since the beginning, the AAVSO has been based on the cooperation between professional and amateur astronomers to collect, archive and analyze variable star data.

Observing variable stars and publishing the observations in astronomical publications had established a toehold in Europe in the 1880’s, but it wasn’t until Harvard College Observatory Director, Edward C. Pickering, began making appeals to American amateurs in the 1890’s that interest began to grow in the United States.

William Tyler Olcott quickly fanned the interest sparked by Pickering into a small fire. Olcott was an amateur astronomer and lawyer who heard Pickering give a talk about variable stars at a meeting of the American Association for the Advancement of Science in 1909. In March 1911, Popular Astronomy published an article by Olcott titled "Variable Star Work for the Amateur with Small Telescopes." Olcott echoed Pickering's earlier appeals to amateur astronomers to use their instruments to engage in citizen science by writing:

“It is a fact that only by the observation of variable stars can the amateur turn his modest equipment to practical use, and further to any great extent the pursuit of knowledge in its application to the noblest of the sciences.”

In October of 1911 the AAVSO was organized. It had 13 members. Headquarters was Olcott’s house on Church Street in Cambridge, MA. William Tyler Olcott single-handedly performed the duties of all the officers while the organization is in its infancy.

In 1912, Henrietta Swan Leavitt discovered the relationship between Cepheid variables period and their luminosity, allowing astronomers to calibrate distances farther out into space than ever before. Variable stars were about to become very important.

In the early days of the AAVSO, observers concentrated on the known long period variables. The variations of these stars were several magnitudes and the periods from maximum to minimum and back were on the order of hundreds of days. This made them ideally suited to careful visual observers armed with comparison charts with assigned magnitudes of comparison stars.

Training observers, organizing and encouraging them, producing and distributing variable star charts and collecting, recording and publishing the results became the responsibility of the officers of the organization. The Director was actually called the Recorder for the first few decades of the AAVSO’s history.

When the AAVSO was incorporated in 1918, there were perhaps a few hundred known long period variable stars. By the time Olcott died in 1936 there were tens of thousands of known variables, far too many for professional astronomers and the observatories of the day to hope to be able to monitor.

To put this era into historical perspective, astronomers were just beginning to sort out the spectral sequence and its meaning. Most believed that all stars started out their lives as hot and bright and got cooler and faded as they matured. The Hertzsprung-Russel Diagram was thought to represent this stellar evolution model, with stars being born on the hot, luminous upper left of the diagram and evolving to the cooler fainter end at the bottom right of the H-R Diagram. What fueled the stars and how long they lasted was still beyond our understanding. The real picture of stellar evolution and the composition and structure of the interiors of stars were still decades away. That amateur astronomers could record the baffling pulsations of variable stars and potentially help unlock the secrets to the stars must have seemed as amazing then as it does now.

Little did they know that variable stars would be fundamental in our understanding of the life cycles of stars and the history and fate of the Universe. Annie Jump Cannon was just sorting out the spectral classes by temperature into the familiar OBAFGKM sequence.

In 1915 Harlow Shapley used Cepheids to figure out the size and shape of the Milky Way, and our solar system’s place within it. That same year, Leon Campbell became Recorder of the AAVSO.

In 1918 Harvard College Observatory offered the AAVSO an office in Building A of the observatory. It was the first of only a handful of addresses the organization would occupy in the first 100 years.

In 1924, Edwin Hubble discovered Cepheid variables in the Andromeda Galaxy. That answered the question of whether the Milky Way was the Universe or merely one among billions of galaxies that populate a Universe much more vast that we imagined. Five years later the amazing announcement that the Universe is expanding was made and not only that, but the galaxies farthest away were receding from us faster than the closer galaxies.

Throughout this time, citizen scientists continued to diligently record and archive the changes of mysterious variable stars, while astronomers examined the cosmos in a whole new light.

Some time in 1942 the AAVSO archived its one-millionth observation. In 1946, after 35 years as the head of the AAVSO, Leon Campbell stepped down as Recorder and Margaret Mayall took over stewardship of the organization. The number and complexity of distributing comparison charts grew exponentially as did the job of collecting and archiving the observations. Then in December 1953, Harvard College Observatory decided variable star science wasn’t important enough to devote office space to anymore, and the AAVSO was asked to vacate HCO by January 1, 1953.

AAVSO Administrative Assistant, Helen Stephanski (left)
and Director Margaret Mayall, 1953.

Kicked to the curb, forced to fend for itself or die, the AAVSO was once again without a formal address. After months of searching, Margaret Mayall found a 400 square foot office in Cambridge to move the AAVSO into. Margaret worked for the AAVSO for free for most of this time and the AAVSO’s 50th anniversary in 1961 came and went without a lot of fanfare or celebration. Just keeping the doors open was an every day challenge.

Technology, computers, the space race and man on the Moon brought about dramatic changes in the world of astronomy in the 60’s and 70’s. In 1965 AAVSO moved again, into slightly bigger offices where it remained for 12 years, and in 1967 the AAVSO entered the computer age with punch card data entry.

In 1974, Janet Mattei became the Director of the AAVSO. Ten years later, the AAVSO International Database contained 5 million observations, and the data was being used by professional astronomers to examine the dynamics of stellar interiors and stellar evolution. AAVSO observers collected information on more types of variable stars than ever before. Cepheids, RR Lyraes, cataclysmic variables, novae, supernovae, R CrBs and some stars that defied classification.

Finally, in 1986, the AAVSO was able to purchase its own building. The AAVSO opened the doors to its new headquarters in August, just around the corner from the offices of Sky and Telescope magazine in Cambridge. The AAVSO had arrived as a force in astronomical research and Janet Mattei and the 25 Birch Street address became familiar to astronomers around the planet.

By the 1990’s the international aspect of the AAVSO was undeniable. Working in cooperation with other variable star organizations in North and South America, Britain, Europe, Australia, New Zealand and Japan as well as having members and active observers in dozens of countries around the world.

In 1995, the AAVSO became accessible to the world via the Internet when it launched its first website. Our connection to NASA and the space and astronomy community became stronger and the AAVSO released Hands On Astrophysics, an educational program aimed at teaching math and science through variable stars, funded by a grant from NASA.

It wasn’t long before astronomers using space telescopes were asking AAVSO observers to monitor cataclysmic variables and other objects from the ground simultaneously while they observed them from space in other wavelengths. Some of our basic understanding of the geometry and structure of accretion disks and the stars in compact binaries came from studies of SS Cygni made by AAVSO observers in conjunction with space satellites. Often times, the satellites would be directed to point at specific targets of opportunity based on reports of stellar activity from AAVSO observers.

In 2002, the AAVSO International Database reached 10.5 million observations. In March of 2004, Janet Mattei, the heart, soul and face of the AAVSO, passed away unexpectedly. It took a year to select a successor, but finally in 2005, Arne Henden became the first Director appointed in the 21st century.

Oddly enough, the AAVSO was facing some of the same challenges it had faced before. The success of the organization had resulted in our outgrowing the Birch Street offices, and when Sky and Telescope announced they were moving and their buildings were for sale, the AAVSO made an offer to purchase and in 2007 moved into the former Sky and Telescope offices.

The AAVSO International Database now contains over 19 million observations and is growing exponentially. Our observers use large sophisticated telescopes, visually and with CCDs to collect more and better observations each year. Some of our observers are able to measure the minute change in light output from a planet crossing in front of a distant star, something William Tyler Olcott could never have imagined.

It is impossible to know where the next one hundred years will lead us, but if you want to be a citizen scientists studying the stars come join us at www.aavso.org.

I’ll leave you with this warning about the addictive nature of variable star observing, experienced by one hundred years of variable star observers.

If you show signs of star susceptibility you should approach the observing of variable stars with the utmost caution. It is easy to become an addict and, as usual, the longer the indulgence is continued the more difficult it becomes to make a clean break and go back to a normal life.

J-E-T-S, Jets, Jets, Jets!

2010-11-26T08:25:00.000-05:00

Bipolar jet from a young stellar object (YSO). Credit: Gemini Observatory, artwork by Lynette Cook

It seems oddly appropriate to be writing about astrophysical jets on Thanksgiving Day, when the New York football Jets will be featured on television. In the most recent issue of Science, Carlos Carrasco-Gonzalez and collaborators write about how their observations of radio emissions from young stellar objects (YSOs) shed light one of the unsolved problems in astrophysics; what are the mechanisms that form the streams of plasma known as polar jets? Although we are still early in the game, Carrasco-Gonzalez et al have moved us closer to the goal line with their discovery.

Astronomers see polar jets in many places in the Universe. The largest polar jets are those seen in active galaxies such as quasars. They are also found in gamma-ray bursters, cataclysmic variable stars, X-ray binaries and protostars in the process of becoming main sequence stars. All these objects have several features in common: a central gravitational source, such as a black hole or white dwarf, an accretion disk, diffuse matter orbiting around the central mass, and a strong magnetic field.

Relativistic jet from an AGN.
Credit: Pearson Education, Inc.

When matter is emitted at speeds approaching the speed of light, these jets are called relativistic jets. These are normally the jets produced by supermassive black holes in active galaxies. These jets emit energy in the form of radio waves produced by electrons as they spiral around magnetic fields, a process called synchrotron emission. Extremely distant active galactic nuclei (AGN) have been mapped out in great detail using radio interferometers like the Very Large Array in New Mexico. These emissions can be used to estimate the direction and intensity of AGNs magnetic fields, but other basic information, such as the velocity and amount of mass loss, are not well known.

On the other hand, astronomers know a great deal about the polar jets emitted by young stars through the emission lines in their spectra. The density, temperature and radial velocity of nearby stellar jets can be measured very well. The only thing missing from the recipe is the strength of the magnetic field. Ironically, this is the one thing that we can measure well in distant AGN. It seemed unlikely that stellar jets would produce synchrotron emissions since the temperatures in these jets are usually only a few thousand degrees. The exciting news from Carrasco-Gonzalez et al is that jets from young stars do emit synchrotron radiation, which allowed them to measure the strength and direction of the magnetic field in the massive Herbig-Haro object, HH 80-81, a protostar 10 times as massive and 17,000 times more luminous than our Sun.

Finally obtaining data related to the intensity and orientation of the magnetic field lines in YSO's and their similarity to the characteristics of AGN suggests we may be that much closer to understanding the common origin of all astrophysical jets. Yet another thing to be thankful for on this day.

Symbiotic Variable Star On the Verge of an Eruption?

2010-11-24T12:52:00.003-05:00

Symbiotic variables are binary pairs in orbit around each other inside a common envelope.

Credit: NASA

November 23rd, astronomers from the Asiago Novae and Symbiotic Stars collaboration announced recent changes in the symbiotic variable star, AX Persei, could indicate the onset of a rare eruption of this system. The last major eruption took place between 1988 and1992. In the (northern hemisphere) spring of 2009, AX Per underwent a short outburst that was the first time since 1992 this star had experienced a bright phase. Now AX Per is on the rise again. This has tempted astronomers to speculate that another major eruption could be in the making.

Symbiotic variable stars are binary systems whose members are a hot compact white dwarf in a wide orbit around a cool giant star. The orbital periods of symbiotic variables are between 100 and 2000 days. Unlike dwarf novae, compact binaries whose periods are measured in hours, where mass is transferred directly via an accretion disk around the white dwarf, siphoned directly from the surface of the secondary, in symbiotic variables the pair orbit each other far enough away that the mass exchanged between them comes from the strong stellar wind blowing off the red giant. Both stars reside within a shared cloud of gas and dust called a common envelope.

When astronomers look at the spectra of these systems they see a very complex picture. They see the spectra of a hot compact object superimposed on the spectra of a cool giant star tangled up with the spectrum of the common envelope. The term "symbiotic" was coined in 1941 to describe stars with this combined spectrum.

The AAVSO light curve of AX Persei from 1970 to November 2010. In the middle is the eruption of 1988-1992. The precursor outburst is the sudden narrow brightening left of the larger eruption. To the right of the light curve you can see the 2009 brightening event. Is this a precursor to a coming major eruption?

Typically, these systems will remain quiescent or undergo slow, irregular changes in brightness for years at a time. Only occasionally do they undergo large outbursts of several magnitudes. These outbursts are believed to be caused either by abrupt changes in the accretion flow of gas onto the primary, or by the onset of thermonuclear burning of the material piled up on the surface of the white dwarf. Whatever the cause, these major eruptions are rare and unpredictable.

AX Per underwent a short-duration flare about one year before the onset of the major 1988-1992 outburst. Now astronomers are tempted to speculate. Could the 2009 short outburst be a similar precursor type event? The present rise in brightness by AX Per might be the onset of a major outburst event similar to that in 1988-1992. The watch begins now, and professional and amateur variable star observers will be keeping a close eye on AX Per in the coming months.

Ranging from 8.5 to13th magnitude, AX Persei is visible to anyone with an 8-inch telescope, and if it erupts to maximum it will be visible in binoculars. You can monitor this interesting star and report your observations to the American Association of Variable Star Observers (AAVSO). Charts with comparison stars of known brightness can be plotted and printed using the AAVSO's Variable Star Chart Plotter, VSP.

Brian G. Marsden (1937-2010)

2010-11-18T12:34:00.017-05:00

It has just been announced in a Central Bureau Electronic Telegram that Brian Marsden died this morning after contracting pneumonia on top of the leukemia he had been fighting this past year.

From Central Bureau Electronic Telegrams #2554:

"He will be remembered as contributing much to celestial mechanics and the dynamics and orbits of minor bodies of the solar system and as having an encyclopedic knowledge of the history of astronomy. He was a dedicated servant to the astronomical community for many decades, serving as Director of the
Central Bureau from 1968 to 2000 (and as Director Emeritus since then) and as Director of the Minor Planet Center from 1978 to 2006 (and as Director Emeritus since then). He also served extensively within Commissions 6 and 20 of the IAU over the years, being past President of both Commissions. And he was one of the most visible astronomers in the world over the years in terms of his generous availability to the news media on behalf of the astronomical community."

Asteroid 1877 Marsden is named in his honor.

From Elizabeth Waagen, via the AAVSO discussion board:

"Dan Green, Director of the Central Bureau for Astronomical Telegrams, just called me (and issued the CBET below) to pass along the extremely sad news that Brian Marsden died this morning (November 18, 2010). He had been fighting leukemia and contracted pneumonia.

Brian was a strong believer in the potential and power of amateur astronomers, and a real supporter of their serious efforts and contributions. From the 1960s on, he was a very good friend of the AAVSO and a close colleague, often asking for assistance to confirm or refute a discovery report before issuing an announcement, request follow-up observation information, or check on the behavior of a star in assessing a report made to the CBAT.

Brian's breadth and depth of knowledge, professionalism, profound concern for the quality of science and information, charm and wit, and great kindness will be sorely missed. Our heartfelt sympathy goes to his wife, Nancy, his family, his assistant and colleague of over 30 years, Dan Green, and all those who worked with him or learned from him.

Elizabeth O. Waagen
Senior Technical Assistant, AAVSO"

For an excellent biography see the Minor Planet Center announcement .

Do Puny White Dwarfs Make Wimpy Supernovae?

2010-11-17T12:09:00.000-05:00

The binary star system J0923+3028 consists of two white dwarfs: a visible star 23 percent as massive as our Sun and about four times the diameter of Earth, and an unseen companion 44 percent of the Sun's mass and about one Earth-diameter in size. The stars will spiral in toward each other and merge in about 100 million years. (Credit: Clayton Ellis (CfA))

Based on results from a radial velocity survey, Warren Brown, (Smithsonian Astrophysical Observatory) and his team have placed a few more pieces into the supernova puzzle.

Supernovae come in many flavors. There are Type Ia, the “standard candles” everyone has heard of; and there are Type Ib and Ic, which also involve binary systems. We also have Type II supernovae that are believed to be the core collapse of single, super-massive stars. There are also super-luminous supernovae, which may be the explosive conversion of a neutron star into a quark star, and finally the weak-kneed cousins of the bunch, the under-performing underluminous supernovae.

Underluminous supernovae are a rare type of supernova explosion 10–100 times less luminous than a normal SN Type Ia and eject only 20% as much matter. Brown and his team have been investigating the connection between underluminous supernovae and merging pairs of white dwarfs.

In the 1980s, on the basis of our theoretical understanding of stellar and binary evolution it was predicted that many close double white dwarfs would exist. However, it was not until 1988 that the first one was actually discovered.

The way to find close double white dwarfs is to take high resolution spectra of the H-alpha absorption line of a white dwarf at several different times and look for variation that is caused by the orbital motion of the white dwarf around an unseen (dimmer) companion. The first systematic searches were not very unsuccessful. Only one system was found. Then, during the 1990s, Tom Marsh and collaborators concentrated their search on low-mass white dwarfs, which, based on current theories, could _only_ be formed in a binary system. In this way a dozen more systems were found.

Extremely low mass (ELM) white dwarfs (WDs) with less than 0.3 solar masses are the remnants of stars that never ignited helium in their cores. The Universe is not old enough to have produce ELM WDs by single star evolution. Therefore, ELM WDs must undergo significant mass loss sometime in their evolution. Producing WDs with 0.2 solar masses most likely requires compact binary systems.

"These white dwarfs have gone through a dramatic weight loss program," said Carlos Allende Prieto, an astronomer at the Instituto de Astrofisica de Canarias in Spain and a co-author of the study. "These stars are in such close orbits that tidal forces, like those swaying the oceans on Earth, led to huge mass losses."

Observational data for ELM WDs is pretty hard to come by because of their rarity. For example, of the 9316 WDs identified in the Sloan Digital Sky Survey, less than 0.2% have masses below 0.3 solar.

NASA/Dana Berry, Sky Works Digital

Half of the pairs discovered by Brown and collaborators are merging and might explode as supernovae in 100 million years or more.

"We have tripled the number of known, merging white-dwarf systems," said Smithsonian astronomer and co-author Mukremin Kilic. "Now, we can begin to understand how these systems form and what they may become in the near future." Unlike normal white dwarfs made of carbon and oxygen, these are made almost entirely of helium.

"The rate at which our white dwarfs are merging is the same as the rate of under-luminous supernovae - about one every 2,000 years," explained Brown. "While we can't know for sure whether our merging white dwarfs will explode as under-luminous supernovae, the fact that the rates are the same is highly suggestive."

At least 25% of these ELM WDs belong to the old thick disk and halo components of the Milky Way. This helps astronomers know where to look for underluminous SNe and where they are unlikely to find them, if the models are correct. If merging ELM WD systems are the progenitors of underluminous SNe, the next generation of surveys such as the Palomar Transient Factory, Pan-STARRS, Skymapper, and the Large Synoptic Survey Telescope should find them amongst the older populations of stars in both elliptical and spiral galaxies.

The papers announcing their find are available online at: http://arxiv.org/abs/1011.3047 and http://arxiv.org/abs/1011.3050.

My Social Network Will

2010-11-16T16:46:00.002-05:00

I make no apologies for being involved with social networking through Facebook, Twitter, LinkedIn and others. I use them every day to network with co-workers, colleagues, associates, friends, family and to meet new people or get introduced to new people.

The good sites work more or less as expected. All of them have their technical glitches, but occasionally something weird or inappropriate happens just because the wheels of the machine keep turning no matter what. It happened to me recently, and it's made me consider what should be done with all my online web pages, social sites, etc. when I'm gone.

LinkedIn kept suggesting I should contact a well-known, highly respected astronomer. Normally I'd take their suggestion and make the effort to reach out, but in this case the person happens to be someone who died suddenly a little over a month ago. It was kinda creepy having the software automatically include him in lists of people I should make a connection with repeatedly. So I decided to do something about it.

Contacting a real person at Facebook, MySpace or LinkedIn is a challenge to say the least, and finding out the process for deactivating a deceased person's account is a real exercise in drilling down into the website. Eventually I was able to fill out a form and someone from customer service emailed me a day later with yet another link to another form that I had to fill out and submit to yet another url address.

Did I mention I'm not related to this departed soul. We weren't friends. I don't know anyone in his family. I just thought it ought to be taken care of out of respect for the person.

Well the issue was finally resolved and they deactivated his account, but like I said earlier, it got me to thinking about what my wishes are for all the places my face, facts and opinions are plastered all over the Internet.

This is how I feel about it today. ( I could change my mind...)

Any career oriented pages or accounts, like LinkedIn or professional associations, should be taken down as soon as possible. If I'm a valued member of some organization and they want to put up an "In Memorium" page or something, fine. (Hey, it could happen!) Try to pick a good picture of me to be remembered by, please.

Facebook and similar pages should be deactivated very soon also. I think its morbid to have Facebook suggest to people that they friend a dead person, so please make my Facebook go away after I'm gone if it's still here by then.

The websites I have online are mostly astronomy related and serve a purpose for an active group of astronomers or researchers. Most of them are shared with at least one other person who can decide whether or not to continue them after I am gone. Maybe they'll all be gone before I am. Who knows.

Considering its minutely small footprint on the memory of Google, and the fact that it is a labor of love written for you as much as for me; leave the blog up forever. Maybe some cyber archeologist will find it one day and get a smile out of "The Summer We Flew to the Moon" or "Don't Lick the Telescope". That thought makes me smile.

The Furor Over FUOrs

2010-11-15T12:25:00.000-05:00

FU Orionis and its associated nebula. Image credit: ESO

In 1937, an ordinary 16th magnitude star in the constellation Orion began to brighten steadily. Thinking it was a nova, astronomers were astounded when the star just kept getting brighter and brighter over the course of a year. Most novae burst forth suddenly and then begin to fade within weeks. But this star, now glowing at 9th magnitude, refused to fade. Adding to the puzzle, astronomers could see there was a gaseous nebula nearby shining from the reflected light of this mysterious star, now named FU Orionis. What was this new kind of star?

FU Ori has remained in this high state, around 10th magnitude ever since. This was a from of stellar variability never seen before. Since there were no other examples of this kind of variable star astronomers were forced to learn what they could from the only known example, or wait for another event to provide more clues.

Finally, more than 30 years later, FU Ori-like behavior appeared again in 1970 when the star now known as V1057 Cyg increased in brightness by 5.5 magnitudes over 390 days. Then in 1974, a 3rd example was discovered when V1515 Cyg rose from 17th magnitude to 12th magnitude over an interval lasting years. Astronomers began piecing the puzzle together from these clues.

FU Orionis stars are pre-main sequence stars in the early stages of stellar development. They have only just formed from clouds of dust and gas in interstellar space, which occur in active star- forming regions. They are all associated with reflection nebulae, which become visible as the star brightens.

This artist's concept shows a young stellar object

and the whirling accretion disk surrounding it.

NASA/JPL-Caltech

Astronomers are interested in these systems because FUOrs may provide us with clues to the early history of stars and the formation of planetary systems. At this early stage of evolution, a YSO is surrounded by an accretion disk, and matter is falling onto the outer regions of the disk from the surrounding interstellar cloud. Thermal instabilities, most likely in the inner portions of the accretion disk, initiate an outburst and the young star increases its luminosity. Our Sun probably went through similar events as it was developing.

One of the major challenges in studying FU Orionis stars is the relatively small number of known examples. Although approximately 20 FU Orionis candidates have been identiﬁed, only a handful of these stars have been observed to rise from their pre-outburst state to their eruptive state.

Now, in the last year, several new FUOrs have been discovered. In November 2009, two newly discovered objects were announced in Central Bureau Electronic Telegrams (CBET) #2033. Patrick Wils, John Greaves and the Catalina Real-time Transient Survey (CRTS) collaboration had discovered them in CRTS images.

The first of these objects appears to coincide with the infrared source IRAS 06068-0641. Discovered by the CRTS on Nov. 10, it had been continuously brightening from at least early 2005 (when it was mag 14.8 on unfiltered CCD images) to its present mag 12.6. A faint cometary reflection nebula was visible to the east. A spectrum taken with the SMARTS 1.5-m telescope at Cerro Tololo, on Nov. 17, confirmed it to be a young stellar object. The object lies inside a dark nebula to the south of the Monocerotis R2 association, and is likely related to it.

Also inside this dark nebula, a second object, coincident with IRAS 06068-0643, had been varying between mag 15 and 20 over the past few years, reminiscent of UX-Ori-type objects with very deep fades. This second object is also associated with a variable cometary reflection nebula, extending to the north. The spectrum of this object also shows H_alpha and the strong Ca II infrared triplet in emission.

Light curves, spectra and images can be found here.

In August 2010, two new eruptive, pre-main sequence stars were discovered in Cygnus. The first object was an outburst of the star HBC 722. The object was reported to have risen by 3.3 magnitudes from May 13 to August 16, 2010. Spectroscopy reported by U. Munari et al in ATel #2808, Aug 23, 2010 support this object's classification as an FU Ori star. Munari and his team reported the object at 14.04V on Aug 21, 2010.

The second object, coincident with the infrared source IRAS 20496+4354, was discovered by K. Itagaki (Yamagata, Japan) on August 23, 2010 and reported in CBET 2426. The object appears very faint (magnitude 20) in a DSS image taken in 1990. Subsequent spectroscopy and photometry of this object by U. Munari showed that this object also has the characteristics of an FU Ori star. Munari reported the object at 14.91V on August 26, 2010.

Both these objects are now the subjects of an AAVSO observing campaign announced October 1, 2010 in AAVSO Alert Notice 425. Dr. Colin Aspin (U. Hawai'i) has requested the help of AAVSO observers in performing long-term photometric monitoring of these two new YSOs in Cygnus. AAVSO observations will be used to help calibrate optical and near-infrared spectroscopy to be obtained during the next year.

Since these stars are newly discovered, very little is known about their behavior. Their classification as FU Ori variables is based on spectroscopy by U. Munari et al. Establishing a good light curve and maintaining it, over the next several years, will be crucial to understanding these stars. This kind of long-term monitoring is one of the things at which amateur astronomers excel.

November 10, 2010, results presenting rare pre and post outburst observations from the Palomar Transient Factory (PTF) show that HBS722 is a bona fide FU Ori type star that was a classical T-Tauri star before eruption, providing strong evidence that FU Orionis eruptions represent periods of enhanced disk accretion and outflow, likely triggered by instabilities in the accretion disk.

Another paper, released the next day, also based on observations from the PTF, shows IRAS 20496+4354 brightened by more than 5 magnitudes, reaching 13.5R in September 2010. Near-infrared spectra appear quite similar to a spectrum of McNeil's Nebula/V1647 Ori, a FUOr which has undergone several brightenings in recent decades.

So after a very slow start, discoveries of new YSOs and our understanding of the dusty disk environments around them are starting to heat up. With new tools and new examples to study we are peering into the the early stages of stellar and planetary formation and finding some of our models have been pretty close to the truth. We expect to find more and similar objects as new all-sky surveys begin to cover the sky, but these objects will still be relatively rare and therefore interesting, because this period in a star's evolution is short-lived and only takes place in the active star forming regions of galaxies.

Images of HBC722 and IRAS 20496+4354 from
Discovery of possible FU-Ori and UX-Ori type objects
Wils, P., Greaves, J. and the CRTS collaboration, Nov 18th 2009.
http://crts.caltech.edu/CSS091110.html

The Infrared Astronomical Satellite (IRAS)

2010-11-14T08:25:00.000-05:00

The Infrared Astronomical Satellite (IRAS) was the first-ever space-based observatory to perform a surveyof the entire sky at infrared wavelengths. Launched on January 25, 1983, its mission lasted ten months. The telescope was a joint project of the United States (NASA), the Netherlands (NIVR), and the United Kingdom (SERC).

It discovered about 350,000 sources, many of which are still awaiting identification. About 75,000 of those are believed to be starburst galaxies, still in their star-formation stage. Many other sources are young stars with disks of dust around them, possibly the early stage of a planetary system formation.

UX Ori type variables

2010-11-14T08:09:00.001-05:00

Artist drawing of the dusty environment around a young stellar object.

Planets are believed to form in these environments when stars are relatively young.

Image credit: NASA

Named after the prototype of the class, UX Ori type variables (commonly called UXOrs) are intermediate mass, pre-main sequence Herbig Ae/Be stars. The light curves of these stars show Algol-like fadings of 1 magnitude or more in random intervals of days to weeks. These fadings are accompanied by a change in color and are thought to be caused by non-uniform dust structure around the star.

AAVSO 3000 day light curve of UX Ori

Pluto Gains Status Among the Dwarfs

2010-11-13T13:03:00.002-05:00

The thing that triggered the unceremonious demotion of Pluto to dwarf planet by the IAU in 2006 was the discovery of several similar Trans-Neptunian objects, namely Makemake, Haumea and Eris. Eris created the biggest problem, because it was estimated to be slightly larger than Pluto. So was Eris the 10th planet? How many more planets were we liable to find? Or were these cold, barren worlds something else?

Rather than have a Solar System with 20 planets, it was decided to redefine "planets" and the sub-category of "dwarf planet' was created to account for this new growing number of smaller objects in the outer reached of the Suns influence.

This week Pluto has regained its status as king of the dwarfs. Eris has turned out to be smaller than Pluto after all.

November 5, a chance alignment provided new data. As Eris crawled along its orbit, some 14 billion km from Earth, it passed in front of a distant star from Earth's vantage point, casting a small shadow across our planet, an event known as an occultation. By timing the duration of the occultation at multiple sites, researchers can estimate the size of the shadow and hence the size of an object.

Combining results from several observatories able to observe the occultation yields a diameter that is "almost certainly" less than the 2340km of Pluto. However, this opens the door on another mystery.

Eris's mass, determined from the orbit of its moon Dysnomia, is about 25% greater than that of Pluto. The newly calculated diameter doesn't change that fact. So if these results hold true, the density of Eris is even higher than we thought. Its albedo (reflectivity) is greater than estimated before too, since it is reflecting light to us from a now reduced surface area. Not long ago this would have thrown serious doubt on the results, but earlier this year astronomers found that the large Kuiper Belt object 50000 Quaoar is essentially a dense rock.

Obviously, these interesting new members of the solar system have plenty of secrets to reveal, and as we find more of them Pluto's status may again change in relation to them, but for today anyway, Pluto is again king of the Kuiper Belt.

Hail, Pluto. Long live the King.

Janet Mattei

2010-10-25T19:01:00.011-04:00

This is a transcript of the 365 Days of Astronomy Podcast for October 26, 2010.

Hi, I'm Mike Simonsen of the American Association of Variable Star Observers (AAVSO).

Dedication
Today, October 26th, is my lovely wife’s birthday, and I’m dedicating this episode to her. Like many amateur astronomers, I’ve spent hundreds of nights over the years out under the stars or hunkered down at my computer instead of cuddling on the couch watching Dancing With the Stars or Survivor with my spouse. Not to mention the tens of thousands of dollars I’ve spent over the years on observatories, telescopes, equatorial mounts, eyepieces, filters, CCDs, software, computers and astronomy related travel. Even the house we live in was chosen in large part for its astronomically friendly dark skies.

Now, my job at the AAVSO requires me to travel to Boston every other month for a week or so, and our standard of living has suffered somewhat, because working for a non-profit is, well, not profitable. As if to add insult to injury, the AAVSO’s annual fall meeting is always around this time of year, and more often than not, over the past ten years, I’ve been away on the day of her birthday, sharing my interest in variable star science with my AAVSO friends, instead of celebrating with the most important person in my life. In fact this year, as you are hearing this podcast, Irene and I are spending her birthday in the car, driving to Boston for another fall meeting.

Yes, my wife is an incredible woman. She has not only survived losing her mother at a tender age and breast cancer, she has survived me, and my astronomical obsessions. I would not be the man I am today without her limitless patience, generosity, compassion and love. Whatever lasting contribution to science I leave behind will be in no small part because of the special woman I married.

The desire to contribute something to science is one of the main reasons people join the AAVSO. Long before “Citizen Science” became a fashionable catch phrase, the AAVSO was encouraging and teaching amateur astronomers how to observe and record observations of variable stars. And when I joined in 1998 the Director of the AAVSO was another very special lady I had the privilege of knowing, Janet Mattei.

Janet Mattei
Janet Mattei was born January 2, 1943, in Bodrum, Turkey. After graduating from high school she came to the United States to study at Brandeis University. She graduated in 1965 but still unsure about what she wanted to do with her life, she worked in a hospital for a year and a half, running its cardio-pulmonary laboratory.

In 1967 she returned to Turkey to teach physics and mathematics. Later, she quit teaching and began graduate studies in astronomy. It was during this time she heard about Dorrit Hoffleit's summer program on Nantucket at the Maria Mitchell Observatory.

The program at Maria Mitchell Observatory gave students an opportunity to do real research. Students would be given their own personal star to research and analyze. Then they would give a report on it at the annual meeting of the AAVSO the following October. Dorrit's decision to hire Janet as her assistant changed her life and the history of the AAVSO forever.

In 1969, the AAVSO had been invited by Dorrit to hold their annual fall meeting on Nantucket. Dorrit was away at a symposium in Virginia and had planned to get to Nantucket just before the AAVSO meeting started, but a sudden blanketing fog prevented her from making it to the meeting on time. Dorrit called the observatory when she knew she wasn’t going to make the opening and asked Janet to take charge until she could get there. As it turned out, Dorrit didn’t arrive until just after the final banquet as everyone was hurrying off to Loines observatory to take advantage of the sudden break in the clouds.

The Director
When Margaret Mayal, the AAVSO Director at that time was looking for an assistant a couple years later it was partly due to Dorrit’s recommendation and Janet’s performance at that meeting that Janet landed the job as assistant to the Director of the AAVSO. Less than a year later, Margaret decided to retire as Director, and though there were several qualified candidates, Janet was elected unanimously by the Council in 1973 to become the next Director of the AAVSO. A job she would hold for the next 30 years.

Janet took charge at an exciting time, as technology was beginning to advance at a breathtaking pace. In the late 70’s space-born telescopes became an important tool in astronomers’ toolbox, and triggering them to observe targets of opportunity was up to the dedicated observers on the ground monitoring cataclysmic variables and other interesting stars. Now space telescopes like Swift alert amateurs on the ground of Gamma-Ray Bursts so they can do follow-up observations of the GRB afterglows.

In the 80’s Janet decided to digitize all of the AAVSO's data, dating back to before the organization's founding in 1911. In 1986 after decades of outgrowing small rented offices, she established AAVSO’s first permanent headquarters building on Birch Street in Cambridge, Massachusetts.

By the turn of the century the AAVSO had grown exponentially in its online presence and prestige in the world of variable star science under Janet’s leadership, but none of it ever went to her head. As leader of the largest variable star organization in the world, the author of over 175 peer-reviewed papers on pulsating and cataclysmic variables and the recipient of dozens of prestigious awards, Janet Mattei was not at all what I expected when I first met her in Hyannis in 1999.

Meeting the Legend

There was supposed to be an outdoor courtyard cookout the night before the meeting took place, a time for all the attendees to meet and greet, but the weather was a little on the cold and wet side so we were forced indoors to one of the hotel meeting rooms. My friend and mentor, Gene Hanson, introduced Irene and I to several of the guests and then we took our seats at one of the tables in the corner.

At the door to the meeting room a group of about a dozen people all suddenly tried to squeeze through at once. At the center of the commotion was a short, brown haired, be-spectacled ball of sunshine and energy directing staff, answering questions from the caterer, smiling and laughing with the cadre of members as they made their way across the room. The center of attention would often disappear behind the others due to her height, but there was no question about her stature.

She made her way around the room, stopping at each table, hugging and shaking hands. She seemed to know everyone’s name, and would ask about their families and pets like an aunt who had just visited a month ago. When she made it to our table Gene introduced Irene and I as newcomers and Janet immediately sat down at our table.

She stayed and talked with us for over a half an hour, asking questions and getting to know all about this new guy from Michigan and his wife. She was warm, approachable, smart and funny. When she finally excused herself from our table Gene turned to me and said, “Do you know how special that was? The Director just sat down and chatted with you for a half an hour!”

All I knew at that point was that I would walk through fire for that woman. Hearing her words and seeing her smile in my mind was warm comfort on many a cold night at the telescope.

I realized later how special that evening was when I finally understood how hard Janet Mattei worked every day of her life, practically single-handedly breathing life into an ever growing organization, nurturing it and its members like a gardener tending her garden. The organization bloomed full into the Internet age with a sophisticated website, online tools to submit and analyze data, real-time email alerts of stellar activity, observing campaigns in support of space telescopes, the development of the High Energy Network to follow GRB afterglows and the advancement of amateur observing capabilities with CCDs.

The Future
She led us all into the 21st century and pointed the way to the future, even as she lay in the hospital fighting leukemia.

"The AAVSO is made up of remarkable, dedicated amateur astronomers," Janet said. "The camaraderie is truly special and unique. I feel that the future holds even more exciting things as more observers extend their observations to fainter targets with CCDs, as more variables are discovered by professional all sky surveys, and as more data become available via the Internet. It's easy to get distracted in view of so many options that we have today. The challenge is to think big, to have a vision, and to move toward that vision."

Her vision wasn’t just about the science. She knew that the people who participate in science are truly our most valuable resource.

Janet lost her battle with leukemia in 2004, but she won the hearts and minds of hundreds of amateur and professional astronomers everywhere in her thirty years of service to the scientific community. Soon I will be back in Cambridge, among my AAVSO friends, and Janet will be there with us as we celebrate her vision and cherish her inspiration. From all of us to you, thank you, Janet.

To my wife on her special day, thank you for your understanding and generosity.

And from me to you, thank you until the next time.

Shine On Harvest Moon

2010-09-23T09:49:00.000-04:00

This is an excellent picture of last night's full moon, the Harvest Moon. The harvest moon is the full moon at or nearest to the autumnal equinox.

Usually, most of the detail is washed out because there aren't any shadows to show depth and texture.

Taken by John Chumack from Ohio, he writes "I could not pass up the chance to nab this Harvest Moon with my telescope from my backyard in Dayton. It was mostly clear, but some high clouds floating around, so I gave it a shot....using a 12 megapixel Canon Rebel Xsi DSLR & my 6" diameter F8 (1219 mm)Cave reflector telescope. It came out very detailed, so I thought I'd share it with everyone.
This is a 1/400 of a second exposure at ISO 400..."

Click on image to enlarge

How's the weather?

2010-09-13T13:44:00.000-04:00

We had very strange weather here last night. It was perfectly clear, calm and a little on the warm side as I crawled into bed around midnight. (The first weekend of football trumps variable star observing)

About 2AM I heard thunder in the distance getting closer. At 3AM it was raining cats and dogs, well actually coyotes.

At 4AM it was perfectly clear again. I could see Orion rising out the window over my pillow and I could hear a pack of coyotes butchering what I think was a deer in the woods about 40 feet from the house. It was loud and scary. The cats upstairs all ducked under the bed.

At 6AM two of the cats were having one of their fake fights where they just hiss and scream at each other then run away.

Irene noticed me getting up and said, "Can't sleep with the cats making that much noise, eh?"

I said, "Yea, and the damn coyotes last night."
She said, "Coyotes?"

I said, "Yea, right after the thunder and rain."
She said "Thunder? It rained?"

Sometimes I wonder if we live in the same house.

Peering Into the Future- The Decadal Survey

2010-08-20T18:01:00.001-04:00

Astronomers are constantly looking into the past. No matter where you look out into space you are seeing things as they were minutes, hours or millions of years ago. Even at 186,000 miles per second, it takes eight minutes for light to reach us from the Sun. It takes four and a half years for light to reach us from the next nearest star, and millions or billions of years to reach us from other galaxies. So astronomers spend a great deal of time looking into the past.

But astronomers also have to look forward, and make predictions about the future. In order to keep astronomical research pushing at the forefront of our knowledge, astronomers need to predict what new areas of research and technology will help answer the pressing science questions of the next decade, and how much it will cost to build the telescopes, spacecraft and experiments needed to unlock the secrets of our Universe. And since it is impossible to pay for everything, someone has to prioritize which projects will get the biggest bang for the bucks in the coming decade.

So every ten years since the 1960’s, astronomers have formed expert panels and committees who coordinate a gigantic undertaking called the Decadal Survey of Astronomy and Astrophysics. Its mission is to survey the field of space and ground-based astronomy and astrophysics, then produce a report recommending priorities for the most important scientific and technical activities for the next decade. The results of the latest Decadal Survey, a massive summary report entitled New Worlds, New Horizons in Astronomy and Astrophysics, has been in the works for nearly two years, and was just released August 13th.

The three key science objectives for the coming decade are laid out in this report. The first is Searching for the First Stars, Galaxies, and Black Holes.

We’ve learned a lot about the history of the universe, from the big bang to the present day. But a great mystery now confronts us: When and how did the first stars and galaxies form out of cold clumps of hydrogen gas and start to shine? When was our “cosmic dawn”?

Observations and calculations suggest that this phenomenon occurred when the universe was roughly half a billion years old. Scientists think that the first stars were massive and short- lived. They quickly exploded as supernovas, creating and dispersing the first elements heavier than hydrogen, helium, and lithium, and leaving behind the first black holes.

After the cosmic dawn, more and more galaxies formed, merged, and evolved as their gases turned into stars and those stars aged. Many of the faintest images from current telescopes are of these infant hungry galaxies. We now know that these cannibalistic galaxies quickly grow black holes in their nuclei with masses that can exceed a billion times the mass of the Sun and they turn into extraordinarily luminous quasars. How this happens is still a mystery.

We also know that the giant galaxies we see around us today were built up from the mergers of smaller galaxies and the accretion of cold gas. Not only do the stars and gas commingle, but the central black holes also merge. We should be able to detect waves in the fabric of space-time— gravitational waves—that result from these dramatic mergers.

Exploring the first stars, galaxies, and quasars is a tremendous challenge, but our ability to look back in time to the beginnings of our Universe improves every year. Astronomers are now looking forward to the time when we can look backward as far as there is anything to see!

The second key science objective is Seeking Nearby, Habitable Planets.

Remarkable discoveries over the past 15 years have led us to the point that we can hope to answer the question, “Can we find another planet like Earth orbiting a nearby star?”

In 1995, a star just like the Sun in the constellation Pegasus was shown to vary regularly in its radial velocity, resulting from the gravitational pull of an orbiting planet. This planet was determined to be roughly as massive as Jupiter but orbited its star every 4 days, far more quickly than any of our Sun’s planets.

So, with a single set of observations we answered an age-old question: yes, there are other planetary systems around stars like our Sun. However, they do not necessarily look like our solar system. Today we know of almost 500 extrasolar planets with masses ranging from a few Earth masses to a few thousand times the mass of Earth. Their orbits, composition and other characteristics continue to surprise us as we learn more about these other worlds.

Radial velocity detection of planets is much more sensitive, reaching down below 10 Earth masses. We can detect tiny changes in the light output of a star as a planet transits in front of it from our perspective here on earth, a technique currently being used by the Kepler space telescope. We can also probe planetary systems by measuring microlensing as their gravitational fields bend rays of light from a more distant star.

Telescopes on the ground and in space have even directly imaged a few large planets as distinct point sources. In other cases, we can learn about planetary systems by measuring infrared and radio emission from giant disks of gas out of which planets are believed to form.

Even more important to identifying Earth-like worlds, the Hubble Space Telescope and the Spitzer Space Telescope have found the spectral lines of carbon dioxide, water, and the first organic molecule, methane, in the atmospheres of orbiting planets. All this in fifteen years is extraordinary progress.

Astronomers are now ready for the next stage in the quest for life beyond the solar system; to search for nearby, habitable, terrestrial planets with liquid water and oxygen. The host star of such a planet may be one like our Sun, or it could be one of the more plentiful but less hospitable cooler red stars.

Cooler red stars are attractive targets for planet searches because light from a planet will be more easily detected above the dimmer light of these cool stars. However, terrestrial planets are relatively small and dim, and are easily lost in the scattered light created by the dusty disks that typically orbit stars.

Armed with new technologies and advances in understanding of the architectures of nearby planetary systems, astronomers hope to meet this challenge in the coming decade also.

The third key science objective for the coming decade deals with the physics of the Universe and is entitled Understanding Scientific Principles.

Astronomy and physics are closely related. For example, observations of orbiting planets furnished verifications of Newton’s law of gravitation and Einstein’s theory of general relativity. The universe is the only laboratory that offers access to special conditions and circumstances not available on Earth, helping us to both understand and discover new elements of the basic laws of nature.

In this past decade we have witnessed the confirmation of the remarkable discovery that the expansion of the universe is accelerating. This acceleration is attributed to the effect of a mysterious substance called dark energy that accounts for 75 percent of the mass-energy of the universe today. The remainder of the mass-energy is comprised of 20 percent dark matter, which is believed to comprise new types of elementary particles not yet found in laboratories on Earth and 4.6 percent regular matter, the stuff we can see and feel directly.

Through our observation of the Universe we have recently learned a very important fundamental fact about the expansion of the universe and the fact that 95 percent of the Universe is beyond our ability to detect! We can only infer the properties of dark energy by measuring its effects on the expansion rate and the growth of structure in the Universe at large.

In the coming decade we hope to answer questions about the state of the universe at a time very soon after the big bang. Recent observations of the cosmic microwave background are consistent with the theory that the universe underwent a burst of inflation when the expansion also accelerated and the scale of the universe grew from its infinitesimally small beginnings to about the size of a person.

Gravitational waves created at this time carry information about the behavior of gravity and other forces during the first moments after the big bang. These waves can be detected through the distinctive polarization pattern that they impose on the cosmic microwave background radiation. Detection of this imprint would help us explore fundamental physics at very high energies and reveal new details about the birth of the universe.

Another opportunity to study fundamental principles in physics comes from precisely observing the behavior of black holes. Black holes are commonly found in the nuclei of galaxies and are born when very massive stars end their stellar lives. Scientists have an exact theoretical description of space-time around black holes but do not know if this description is correct. One way to find out is to observe X-ray-emitting gas and stars as they spiral toward a black hole’s event horizon, a place beyond which nothing, not even light, can escape. Another is to observe the jets that escape black holes with speeds close to that of light.

However, the best test of all will come from measuring the gravitational radiation that is observed when moderate-mass black holes merge. We now have the software and the computing power to calculate the signals that should be seen and the technology to test the theory.

The experiments and tools proposed to investigate these key scientific questions are as remarkable as the questions themselves. Satellites that fly in formation to detect gravity waves in space, a space-born Wide-Field Infrared Survey Telescope designed to explore the acceleration of the expansion of the Universe and hunt for earth-like planets, and the Large Synoptic Survey Telescope, a wide-field telescope to study variable sources and address questions that range from asteroids that threaten Earth to the nature of dark energy.

We can look forward to exciting new discoveries in the near future as astronomers explore our distant past with instruments that haven’t even been built yet.

Carnival of Space #166

2010-08-10T07:20:00.000-04:00

This week's Carnival of Space, the 166th edition, is hosted by The Gish Bar Times, the only blog dedicated to Jupiter's volcanic moon, Io.

Gish Bar Times we covers Io-related news, including new volcanic eruptions, published papers and conference abstracts, new images (or reprocessed older images), and news regarding upcoming missions to the Jupiter system.

This week's Carnival is presented in roughly chronological order, from older to newer developments in astronomy and space science. Cruise on over, check out the carnival and find out all about Jupiter's innermost moon.

The Stories Behind the August Perseids

2010-08-08T09:56:00.003-04:00

It's August, so for better or worse, two stories will be making the rounds in the blogosphere. First, is the Mars Hoax email that will not die. I've written about this before, so we won't go there again. Second, is the Perseid meteor shower, which occurs every August.

The Perseids are my favorite meteor shower because the late summer weather is a lot easier to tolerate than some of the cold winter nights other annual showers happen to occur, like the Leonids in November and the Geminids in December.

Every August that the Moon promises not to interfere, we are reminded that this will be the best meteor shower of the year. But there is more to the Perseids than meets the eye and there are some interesting stories behind the Perseids that don't generally get told. I'd like to share some of them with you here.

Let's start with where do meteor showers come from?

We know today that there are streams of particles, called meteoroids, in orbit around the Sun. When the Earth encounters one of these streams, these mostly dust sized particles are trapped by Earth's gravity and burn up as they descend through the atmosphere. The result of this flame-out is a meteor, or what people commonly refer to as "a shooting star."

But where do these streams of meteoroids come from?

In the 1800's Giovanni Schiaparelli was the first to suggest that meteor showers were associated with periodic comets. Schiaparelli noted the orbits of some periodic comets coincided with the orbits of streams of particles responsible for meteor showers. One of these, Biela's comet, discovered in 1826, was identified by Austrian astronomer Wilhelm Baron von Biela as a periodic comet that returned every 6.6 years.

Biela's comet put on quite a show on subsequent returns after its discovery. It was seen to break apart into two pieces in 1846, and in 1852 the two fragments returned as twin comets! The remains were assumed to have disintegrated entirely since the comet was never seen again. In 1872 and 1885, however, when Earth crossed the path of the comet’s known orbit, bright meteor showers known as Andromedids (or Bielids) were observed. This seemed to prove the idea that meteor showers are composed of fragments of disintegrated comets. Schiaparelli was also the first to show that the Perseid and Leonid meteor showers were associated with comets.

Today we know several annual meteor showers and their connection to periodic comets. The eta Aquarids and Orionids are associated with the famous comet 1P/Halley. The Southern Taurids are associated with comet 2P/Enke. I've already explained that the Andomedids come from comet 3P/Biela, the comet that broke into two pieces and then disintegrated entirely. The Leonids come from debris left behind from comet 55P/Temple-Tuttle and, getting back to our August astronomy story, the Perseids occur when Earth encounters the stream of dust left behind from comet 109P/Swift-Tuttle.

And here is another story within a story, the naming convention for comets. What is all this 1P/ and 2D stuff all about?

The exact rules for comet nomenclature are pretty involved, but essentially the letter P stands for a periodic comet with a period of less than 200 years. C stands for a comet that is not periodic, and D stands for a comet that has broken up or been lost, a dark comet. The names associated with comets are most often the discoverer or co-discoverers of the comet, although some of them, like Halley's Comet are named after the astronomers who first calculated their orbits rather than their original discoverers. The number corresponds to the order and number of discovery of that type of comet. 109P/Swift-Tuttle, the comet responsible for the Perseid meteor shower each year, is therefore the 109th periodic comet known, and it is named after its co-discoverers, Swift and Tuttle; which leads us to two more stories behind the story of the Perseid meteors.

Who were Swift and Tuttle?

Lewis Swift was born in Clarkson, New York on February 29, 1820. Swift was a farmer and hardware store owner by trade. Between 1866 and 1892 he discovered thirteen comets, making him one of the most prolific comet discoverers of all time. Lewis Swift's life story is one of pain, perseverance, disappointment, delight, fame and fortune.

According to Swift, he first really became interested in astronomy after observing the Great Comet of 1843. This comet was so bright it could be seen in broad daylight and its tail extended 40 degrees across the sky!

Swift made his first telescope, a 3-inch refractor with a lens purchased for $5.00 from the Spencer Optical Company. In 1858 the 3-inch was accidentally broken, so Swift purchased a 4 1/2-inch 'comet seeker' from the American optical craftsman Henry Fitz. This was the telescope he made all but one of his comet discoveries with. His early observatories weren't much more than small platforms built on the roof of his barn, accessed through a hole cut in the roof.

His first comet discovery, and the one he is most famous for, was actually quite by accident. Upon hearing of the discovery of a comet in the northern sky, near Polaris, the North Star, Swift decided to observe the comet one July evening in 1862. After less than five minutes he came across a beautiful comet that he took for granted was the comet he had been looking for. After following the comet for several nights it become clear that this was actually a different comet. In fact, it was the same comet that Harvard astronomer Horace Tuttle had independently discovered a few days after Swift.

It was in 1866 that Giavonni Shiaparelli announced that comet 1862III (Swift-Tuttle) traveled in an orbit virtually identical to the Perseid meteor stream. Swift and Tuttle argued bitterly for years over who deserved credit for this important comet's discovery.

In 1872, Swift moved to Rochester, New York and opened a hardware store. He became well known for discovering comets with his 4 1/2-inch telescope from the roof a local cider mill. As his popularity increased, he began to give lectures on astronomy and often held what we now call star parties, showing people comets and other celestial wonders in Lake View Park.

In 1879, Swift found a generous patron in Rochester patent medicine businessman Hulbert Harrington Warner, who financed the building of an observatory for Swift. Warner assured "Professor Swift" as he had become known, that if Swift could raise the money to purchase a large telescope, Warner would build an observatory for it. The original estimate for construction of the observatory was $20,000.

Swift was able to fulfill his part of the bargain by collecting donations for a 16-inch Alvan Clark & Son telescope from the people of Rochester, NY. When the observatory opened it was the fourth largest telescope in the United States. The plans for the observatory also called for an astronomical library, an elevator and a residence for Professor Swift and his family. Ultimately, the Observatory cost Warner $100,000.

The observatory itself was the first observatory in the world to encourage visits by the general public. All a visitor had to do was buy a ticket for 25 cents at Warner's business on St. Paul Street. It became so well known that it was included in travel guidebooks.

Soon after the observatory opened in 1882, Swift closed his hardware store and became, for all intents and purposes, a professional astronomer. Swift's attentions soon turned from comets to nebulae. While Charles Messier had considered them to be mostly annoyances to the discovery of comets, Swift believed they were worthy of study in their own right. By the end of his career he had discovered over 1200 objects, ranking him third behind the Herschels and number one among American observers.

He was awarded an honorary Ph.D. from Rochester University, and received more medals than any other astronomer of his time, including three from the Imperial Academy of Science in Australia, four from the Astronomical Society of the Pacific, and the Laplace Medal from the French Astronomical Society. In 1897 he was the first person awarded the Jackson-Gwilt Medal of the Royal Astronomical Society.

In 1893, motivated largely by the construction of an Episcopal church next door to the observatory that blocked his view to the sky, Swift relocated the 16-inch telescope to Lowe Observatory on Echo Mountain in California, where he spent the remainder of his career. Swift discovered his last comet in 1899 at the age of 79. Although some of his comet discoveries can surely be said to be lucky, most were the result of persistent, systematic, tireless observations. Swift was known to remark often, "One cannot discover comets lying in bed."

The second half of the story behind the discovery of Comet Swift-Tuttle is Horace Parnell Tuttle. Born March 17, 1837 in Newfield, Maine, Horace's life story is a bit more of a mystery.

Charles Wesley Tuttle, Horace's older brother, was an amateur astronomer who constructed his own telescope, and upon visiting the Harvard Observatory so impressed observatory director, William Bond, he was hired as an assistant observer. This was Horace's connection and eventual inroad to working at Harvard Observatory later on.

Charles was eventually replaced at Harvard by his younger brother Horace as an observatory assistant. Horace became attached to the observatory's four-inch Merz comet seeker, which he used on the balconies of the observatory of the 15-inch refractor, spending night after night in search of new comets. While not as prolific as Swift, Horace Tuttle proved to be a successful comet hunter.

He discovered or co-discovered numerous comets, including 55P/Tempel-Tuttle, parent body of the Leonid meteor shower, 109P/Swift-Tuttle, parent body of the Perseid meteor shower, and the "Great Comet of 1860." Other comets that bear his name are 8P/Tuttle, parent comet of the Ursid meteor shower, 41P/Tuttle-Giacobini-Kresak and C/1861 Y1 Tuttle. In 1859 he was awarded the Lalande Prize of the French Academy of Sciences for discovering of two comets in one year (1858).

With the outbreak of the Civil War, Horace Tuttle enlisted in the 44th Massachusetts Volunteer Infantry and served at New Bern, North Carolina. He continued to make astronomical observations during the war, reporting on the appearance of Comet Tempel 1864 II.

The war had taken Tuttle out of comet seeking for three and a half years, so his discovery of comet 1866 I at the U.S. Naval Observatory on January 5th, 1866 must have felt pretty good after such a long hiatus. This was Comet Tempel-Tuttle, first discovered by the French astronomer, Tempel, more than two weeks earlier. Tuttle received a lot of press for this discovery since it was only the second comet ever discovered at the Naval Observatory.

In 1887 Tuttle obtained a 6.5-inch broken-back reflecting comet seeker, made for him by John Brashear. It was installed on the roof of the Naval Observatory, where he made his last comet discovery, a recovery of Comet 1888V Barnard.

Tuttle lived in the Washington, D.C. area from about 1884 until his death in 1923. In his final years he was feeble and blind. His gravesite is unmarked and its location is unknown.

Comet Swift-Tuttle itself is a pretty intersting story. It is the largest object known to make repeated passes near the Earth. It is also one of the oldest known periodic comets with sightings by the Chinese as far back as 68 B.C. The best estimate of when it will return is July, 2126.

The first attempt at computing a definitive orbit was made in 1889, when F. Hayn determined the orbital period to be 119.64 years. In 1971, Brian Marsden and Zdenek Sekanina took 212 positions obtained during the period of July 22 to October 22, 1862, applied perturbations by all nine planets, and came to a similar conclusion, 119.98 years.

A couple of years later, Marsden considered the possibility of linking Swift-Tuttle to an earlier comet. He found two in the 18th century that looked promising--1737 (Kegler) and 1750 (Wargentin). The 1750 comet appeared at just about the right time, but the 1750 comet seemed to be moving too fast to fit the orbital calculations. The 1737 comet actually exhibited a motion consistent with what would have been expected for Swift-Tuttle but the comet's period would have to have been some 10 years longer than was indicated by the observations in 1862.

Marsden made two predictions for a forthcoming return. First, using the definitive orbit calculated by Sekanina and himself, he suggested a perihelion date of September 16, 1981. Second, he suggested that if the link to the comet of 1737 was valid, Swift-Tuttle would most likely return to perihelion on November 25, 1992.

Initial searches for the comet began in 1980, which was within the error range given by calculations, and more rigorous searches were conducted in 1981 and 1982, but the comet was not recovered.

On September 26, 1992, Tsuruhiko Kiuchi, from Japan, discovered a comet and reported it to the National Astronomical Observatory in Tokyo. Several observers were able to confirm the comet within the next 24 hours and the direction and rate of motion were consistent with what would be expected for Swift-Tuttle. The long lost parent of the Perseid meteor shower had indeed returned.

After refining the calculations of its orbit and looking at predictions of its next return, there was some concern that Swift-Tuttle might actually collide with Earth in 2126!

The comet has a diameter of 10 kilometers, and if it did hit the Earth going 60km/sec, it would be catastrophic. The collision would be 1 billion times more powerful than the atomic bomb dropped on Hiroshima. An impact similar to this is believed to have caused the extinction of the dinosaurs. Swift-Tuttle crashing into the planet could create a cloud of dust that would block out the sun, killing all plant life, and causing an ice age.

What are the chances it will hit? It's difficult to estimate. The comet will only collide with the Earth if the two bodies occupy the same space within a narrow three and a half minute window of their orbits. A difference of one hour would cause the comet to miss the Earth by about 100,000 kilometers. Considering the last calculations were off by 10 years, you can imagine how difficult it is to be sure one way or the other.

We haven't heard the last of comet 109P/Swift-Tuttle. In less than 120 years our ancestors will be learning about Professor Swift's comet as it makes another pass through the inner Solar System, leaving a trail of meteoroids behind to delight another generation with August meteor showers for another 130 years.

John Greaves

2010-08-07T11:41:00.000-04:00

A Simostronomy exclusive!

This is one of the only pictures of John Greaves known to exist. You can also see the remains of some unfortunate astronomer roasting on a spit in the background.

The Perseid Meteor Shower of 2010

2010-08-05T08:52:00.000-04:00

By now you may have heard that the Perseid meteor shower is liable to be a good one this year. We've even gone so far as to change the date of our annual barbecue/star party from September to August 14 to coincide with what we hope will be some celestial fireworks worth staying up for. The Perseid meteor shower is one of the most consistent performers and the meteors produced are some the brightest of all meteor showers. Perseid meteoroids enter the atmosphere at 60 km/sec, and the resulting meteors often leave behind persistent ionization trains.

New Moon occurs just prior to the peak of the shower so there will be no interference from moonlight. Some meteors are only 5th magnitude, or fainter, and can easily be lost to the glare of the Moon for the fleeting seconds we see them disintegrate in the atmosphere. A clear, dark, moonless night is perfect for catching all the meteors, not just the biggest and brightest.

The Perseids get their name from the point in the sky they appear to come from, called the radiant. If you could draw an imaginary line back through the trail of all the meteors you would see them converge on a single point in the constellation Perseus. This is because the Earth is moving through space and encounters a stream of particles left behind from Comet 109P/Swift-Tuttle each year. The radiant is the direction we are heading as we plow through this debris more or less. Very similar to snow rushing at your windshield as you drive through a storm, regardless which direction it's actually going as it falls.

The shower is visible from mid-July each year, with the peak in activity falling between August 9 and 14. During the peak, the rate of meteors reaches 60 or more per hour. The rate is highest after midnight, since the side of the Earth facing into the oncoming dust cloud scoops up more particles as it moves through space.

Watching a meteor shower is fun and easy. You don't need any special equipment. Meteors travel so far across the sky so quickly it is impossible to watch or track them with a telescope or binoculars. The best way to observe them is just like you would watch a good fireworks display. Set up a blanket, sleeping bag or better yet a lounger, bundle up warm and look up at the sky. You may want to face northeast, towards the shower radiant, but if that view is partially obstructed don't worry, meteors will be seen all across the sky. You can count how many you and your friends see in an hour for fun, or you can set up a more serious meteor counting team and keep accurate records to report to various organizations later.

Astronomers use the term Zenithal Hourly Rate (ZHR) to describe the rate of meteors coming from a particular shower. The ZHR of a meteor shower is the number of meteors an observer would see in one hour under a clear, dark sky if the radiant of the shower were at the zenith. Your mileage may vary, and is almost always lower because the radiant is rarely at the zenith. In 2009, the Perseid peak Zenithal Hourly Rate was about 120, but fainter meteors were washed out by a waning gibbous moon. The ZHR for 2010 is expected to be about the same, peaking in the morning hours of August 12 and 13. Make plans to get away from city lights and go watch one of natures better fireworks displays this month.

Carnival of Space #164

2010-07-28T08:48:00.000-04:00

The 164th Carnival of Space is now online at The Next Big Future blog. Check out this week's diverse offerings.

Nextbigfuture is the Lifeboat Foundation Technology Research News Website. The Lifeboat Foundation is a nonprofit nongovernmental organization dedicated to encouraging scientific advancements while helping humanity survive existential risks and possible misuse of increasingly powerful technologies, including genetic engineering, nanotechnology, and robotics/AI, as we move towards a technological singularity.

A Question of Identity

2010-07-23T08:38:00.000-04:00

KAIT telescope

Question: When is a supernova not a supernova?

Answer: Now that's an interesting story...

It all started on Christmas night 2005, when astronomers using the Katzman Automatic Imaging Telescope (KAIT) in California discovered an apparent supernova not far from the center of the elliptical galaxy NGC 2274. There was nothing there on an image they had taken two weeks prior. Twelve hours later, Astronomers at the National Astronomical Observatory of China confirmed the 18th magnitude object was real. It was named SN2005md and the discovery was announced in CBET #332 on December 26.

A spectrogram taken on December 28 showed it to be most probably a "young Type-II supernova". This was announced in an IAU Circular (8650) on the 29th of December. Subsequent KAIT images showed that SN2005md faded rather quickly and it was fainter than magnitude 19.8 by January 2006.

Normally that would be the end of the story, but this time it wasn't.

First, it is generally accepted that the progenitors of core-collapse supernovae are massive young stars. These massive young stars are almost always found in spiral or irregular galaxies dominated by young stellar populations.

NGC 2274 is a strangely shaped early irregular galaxy (an E-type galaxy), so SN2005md was unusual. In fact, it was only one of 22 examples found in an extensive literature search of all early irregular galaxies containing core-collapse supernovae in history.

A paper published in 2008 by Hakobyan et al. (2008, A&A, 488, 523) examined all these cases and found that 19 of the galaxies had been mis-classified, and were actually spiral (17), irregular (1) or ring (1) galaxies. Of the 3 remaining galaxies with early type classification, one (NGC 2768) is a suspected merger remnant, another (NGC 4589) is definitely a merger, and the third (our NGC 2274) is in close interaction with another galaxy. This seemed to explain the contradiction of core-collapse stars residing in old non-star-forming irregular galaxies, since some amount of young stellar population in these interacting galaxies is expected.

Well then, all was right in the Universe once more...or was it.

In February 2008, while Hakobyan and company were putting the final touches to their paper for submission, an electronic telegram (CBET 1265) was issued announcing that either a new supernova in NGC 2274, very close to the position of SN2005md has erupted at magnitude 18.5, or that SN2005md itself had suddenly re-brightened!

The difference between the previously reported position of SN2005md and the "new" object was on 0.1 arc seconds in R.A. and 0.4 arc seconds in declination, but at the distance of NGC 2274 (estimated to be 70 mega parsecs) that could mean they were unrelated objects 120 parsecs apart. Measuring the exact positions of anything that faint close to a galaxy is tricky business and the likelihood they were the same object seemed greater than the probability they were two SN in the same galaxy that close together.

The fact that the previously reported spectrum only showed a featureless blue continuum, with no obvious broad supernova features, and that the object faded so quickly added to the suspicion that SN2005md wasn't a supernova at all.

The telegram went on to explain if the new object was indeed a re-brightening of 2005md, possible explanations were that it was the super-outbursts of a luminous blue variable (LBV), or multiple flares of the LBV as part of an extended eruption. Other possible explanations included a Galactic variable star or a background AGN/blazar.

Needless to say, SN2005md was a mystery. Further observations were encouraged.

Flash forward to July 2010. Astronomers Telegram (ATEL) #2750 finally sorts it all out for us. A fully reduced spectrum taken with the LRISp on the Keck I 10 meter telescope on December 31, 2005 shows that the object originally classified as a young Type IIb supernova is in fact a galactic cataclysmic variable. That's right, it's in our own Milky Way galaxy. NGC 2274 just happens to lie in the background very close to its position on the sky. The CVs spectrum shows features typical of a dwarf nova in outburst. The Balmer emission lines were the clincher. They have an average redshift of about 300km/second, which is far to little to be part of a galaxy estimated to be receding from us at 5000+km/second.

This also explains the re-brightening in 2008, since CVs are prone to outburst over and over on various timescales from weeks to years. It also resolves the conundrum of having a core-collapse supernova in an E-type galaxy with few signs of active star formation.

And once again, order has been restored to the Universe.

The only mystery that remains is why it took them so long to figure this out. The spectrum that resolved this issue was obtained New Years Eve, 2005!

Black Holes

2010-07-19T09:50:00.000-04:00

Here is a great new video from the National Science Foundation on black holes, large and small.

The Planet With a Tail

2010-07-16T15:27:00.000-04:00

Today there is a new tail to add to the tale of astronomical tails. This one belongs to a planet.

Comet McNaught Credit: Robert McNaught

You're all familiar with the beautiful tails that comets display as the go around the Sun. Energy from our star ionizes particles and strips dust away from the comet's nucleus to form these sometimes magnificent tails.

Mira, one of the most famous variable stars, also sports a tail. Mira is an old evolved red giant star that is losing massive amounts of surface material as it hurdles along through space. This tail material, imaged for the first time in 2007, has been released over the past 30,000 years. Coincidentally, Mira happens to reside inside the tail of the constellation Cetus the Whale.

Image credit: NASA/JPL-Caltech

The common factor in the formation of these tails is a strong stellar wind emanating from the star; our Sun in the case of comets, and the wind from the red giant Mira in the case of the variable star.

Now astronomers have discovered evidence for a planet sporting a tail caused by this same phenomena, the stellar wind of the star HD 209458. The gas giant planet, named HD 209458b, is orbiting so close to its star that it only takes three and a half days to orbit the star. As a result of this uncomfortable proximity its super-heated atmosphere is being blown off into space. Observations taken with Hubble's Cosmic Origins Spectrograph (COS) suggest this cast-off atmospheric material is accumulating behind the scorched planet forming a comet-like tail.

Image credit: NASA, ESA, and G. Bacon (STScI)

"Since 2003 scientists have theorized the lost mass is being pushed back into a tail, and they have even calculated what it looks like," said astronomer Jeffrey Linsky of the University of Colorado in Boulder, leader of the COS study. "We think we have the best observational evidence to support that theory. We have measured gas coming off the planet at specific speeds, some coming toward Earth. The most likely interpretation is that we have measured the velocity of material in a tail."

The star is not just blowing off the top layers of the atmosphere either. COS detected carbon and silicon in the planet's super-hot, 2,000-degree-Fahrenheit atmosphere. This means the parent star is heating the entire atmosphere, dredging up heavier elements and allowing them to escape the planet along with the lighter gases.

Considering the continuous loss of material into space, how long before this planet simply evaporates? "It will take about a trillion years for the planet to evaporate," answered Linsky.

Timothy Ferris Narrates Epsilon Aurigae Video

2010-07-15T16:27:00.000-04:00

This is a new planetarium show trailer developed for the Citizen Sky project, narrated by Timothy Ferris and developed by the California Academies of Sciences Morrison Planetarium, directed by Ryan Wyatt.

Carnival of Space #162

2010-07-14T07:27:00.000-04:00

The latest Carnival of Space is hosted by Paul Sutherland over at the Skymania blog. Skymania's pages offer the latest astronomy and space news, observing tips and advice on choosing a telescope. Check out the Carnival and browse the other regular offerings at Skymania.

The Ninth Planet

2010-07-07T15:46:00.001-04:00

Hey, to me it's still a planet. So it's a dwarf planet; that doesn't matter to me. A red dwarf is still a star. Anyway... I am not trying to continue that debate here. Instead, I'd like to show you an incredible image taken by my friend, John Chumack, from Ohio. It is of Pluto crossing in front of the dark nebula Barnard 92. This chance passage made it much easier to pick out Pluto among the rich star field of M24 The Sagittarius Star Cloud. This is one of the things that makes John such a great astrophotographer. Researching and grabbing great shots like this.

This image was taken from John's observatory in Yellow Springs, Ohio, using John's homemade 16” Newtonian telescope and a QHY8CCD single shot color camera. The Exposure was 1 hour (12-5 minute subs) captured from 01:00am until 02:00 am E.S.T. on 07-06-2010.

John writes, "Although Pluto was easily visible in a short 5 minute exposure, I took an hour exposure to show the Dark nebula and 'Rich & Pretty' surrounding star field."

Image credit: John Chumack

http://www.galacticimages.com/

Click to enlarge- really- go ahead, it's pretty cool.

Congratulations, it's a Supernova!

2010-07-01T16:05:00.000-04:00

Last night after dinner, I laid down to take a nap (I start observing
around midnight or so in summer). I heard a message come in on my
phone, so I checked to see if it was anything important. As it turns
out, it was an urgent plea for help from Bob Moore (Caroline Moore's
dad, the teenage girl who discovered a SN at age 14). He is trying to
confirm a suspected SN discovery but can't find any useful comparison
stars near the obscure galaxy he is examining, can I please help?

Mind you, I only get a few hours sleep a day when its clear, so I was
thinking, "shit, why did I have to check that message."

Well, Bob is a friend and I know how excited I would be if I thought I
had a SN discovery, so I called him, got the information and went back
down to the office to see if I could help him. After maybe 45 minutes
or so I had put together some reasonable photometry for him to measure
his SN with, emailed him the chart and wished him luck. I fell asleep
quickly after that.

Around lunch time today, I called Bob to see if there was any news
yet; had it been confirmed? "Nothing yet", he said, but Mike Peoples
and collaborators were pretty sure they had confirmation images from
California.

About an hour ago the Telegram from the IAU announcing the discovery
of SN 2010ew popped up in my mailbox. I forwarded a copy to Bob with
the title "Congratulations, It's A Boy".

I'm happy for you Bob et al, but don't call me after 6PM tonight. I'm
really tired now, and it's going to be unmercifully clear here for
days on end. I need some sleep.

*******************************************************

Electronic Telegram No. 2345
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director: Daniel W. E. Green; Room 209; Dept. of Earth and Planetary
Sciences; Harvard University; 20 Oxford St.; Cambridge, MA 02138; U.S.A.
e-mail: cbat@iau.org; cbatiau@eps.harvard.edu
URL http://www.cfa.harvard.edu/iau/cbat.html

SUPERNOVA 2010ew
M. Peoples, J. Newton, and T. Puckett report the discovery of an apparent
supernova (mag 16.6) on unfiltered CCD images (limiting mag 18.5) taken with
a 0.40-m reflector at Portal, AZ, U.S.A., on June 28.39 UT in the course of
the Puckett Observatory Supernova Search. The new object, which was confirmed
at mag 16.6 on images (limiting mag 19.8) taken by P. Mortfield and S.
Cancelli on June 29.48 with a 0.40-m reflector at Sierra Remote Observatories
in California, is located at R.A. = 18h37m11s.88, Decl. = +30o37'49".6
(equinox 2000.0), which is 4".6 west and 7".1 north of the center of the
presumed host galaxy. Nothing is visible at this position on images taken by
Puckett on June 13 (limiting mag 19.1); however, T. Orff reports a precovery
image (limiting magnitude of 18.5) taken by Puckett on June 20, which shows
2010ew at mag 17.1.

NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
superseded by text appearing later in the printed IAU Circulars.

(C) Copyright 2010 CBAT
2010 July 1 (CBET 2345) Daniel W. E. Green

Pickering's Women

2010-06-21T22:16:00.000-04:00

Today I’m going to introduce you to some of the most famous women in astronomy. They were all employed by the Harvard Observatory, in the late 1800’s to early 1900’s. There were no Apple’s or PCs back then. Instead, human ‘computers’ did all the calculations used in astronomical research. Out of 80 or so women who worked for Harvard during this time, four of them distinguished themselves as astronomers in their own right, in spite of being discouraged at every step by the prejudices of the day.

Harvard College Observatory was founded in 1839. Astronomy was just beginning to be taught as a science in its own right, instead of as an extension of philosophy. Universities were beginning to receive funds for astronomical research, and data was beginning to accumulate faster than it could be analyzed. In 1877 Edward Charles Pickering became the director of the observatory, and it is he who is responsible for opening the doors of astronomy to women.

Although women had been volunteers at the observatory in the past, usually relatives of men on Harvard’s payroll, Pickering convinced the Harvard Corporation to hire women for the tedious work of computing. The women computers at Harvard College Observatory became known as “Pickering’s Harem”. He paid them half what men were paid to do this work, so he was able to afford twice as many workers. This proved to be important because Harvard was about to take on the monumental task of photographing and cataloging the entire sky; the Henry Draper catalog.

Henry Draper, was a wealthy physician, an amateur astronomer, and a pioneer in the field of astrophotography. He recorded the first stellar spectrum, which he took of Vega in 1872. He took the first photograph of an astronomical nebula, recording the Great Orion Nebula in 1880. He obtained the first wide-angle photograph of a comet’s tail, and the first spectrum of a comet’s head in 1881. Draper invented the slit spectrograph and pushed the state of the art in photography, optics, and telescope clock drives.

His great ambition was to photograph the entire night sky, to create a complete spectral catalog that would be available for astronomical research. He did not realize his dream due to his untimely death at the age of 45. His widow, Anna Mary Palmer, did not let his dream die. She donated money to the Harvard College Observatory to complete this monumental task in honor of her husband.

Williamina Fleming was born in Scotland in 1857. Mina, as her friends and family called her, attended public schools, where at the young age of 14, she began student teaching. Her teaching career lasted six years until 1877, when she married James Orr Fleming. The young couple sailed to America in December 1878 and took up residence in Boston, Massachusetts. A few months later, James abandoned his wife, and his unborn child.

Fleming found herself in a strange country, alone, pregnant, and in need of money to support herself. She found employment as a housekeeper. Her new employer was Edward Charles Pickering, the director of Harvard College Observatory.
Not long after Fleming began working in Pickering’s household, he offered her a position at the observatory. One story abut how this came to be is that Pickering, unsatisfied with the work of a male assistant at the observatory, complained that his housekeeper could do better work. She did do a better job than his previous assistant and in 1881, she became a permanent member of the observatory staff.

Five years later, in 1886, the Harvard College Observatory received funding from Anna Draper to compile her husband’s catalog project. Williamina was responsible for cataloging, indexing, examination, and care of the new photographic plates. The “computers” were responsible for identifying the stars on the plates and then calculating their positions. Twelve years later, the Harvard corporation officially recognized Fleming’s position. In 1898 she was bestowed the title of Curator of Astronomical Photographs, becoming the first woman to receive an appointment of this kind.

It was also her responsibility to catalog the plates so they would be accessible and the data readily available. She devised her own spectral classification system, after discounting the system devised by Father Angelo Secchi as too simplistic to account for the wide variety of stellar spectra. Fleming’s system divided the stars into classes, from A to Q, and was based on the complexity of the spectrum lines and bands and the strength of the spectral lines due to hydrogen. Stars that did not fall neatly within a category were grouped into Q.

In 1890, the first Henry Draper Catalogue was published in the Annals of the Harvard College Observatory. It contained most of the stars visible to the unaided eye, a total of 10,351 stars. Though Fleming was not listed as an author, Pickering did acknowledge her contribution to the work. She was also widely recognized by the astronomical community.

During Fleming’s tenure at Harvard, she discovered many celestial objects, including 10 novae, 94 Wolf-Rayet stars, and 222 long-period variables. She also received many honors and awards, including memberships in the Royal Astronomical Society and the Astronomical Society of Mexico.

Fleming worked at Harvard College Observatory until her death at age 54 in 1911.

Antonia Maury was born in Cold Spring, New York in 1866. Her father was a protestant minister and her mother, Virginia Draper Maury, was Henry Draper’s sister. Maury graduated with honors from Vassar College in 1887 and was a student of Maria Mitchell.

Maury was hired by Pickering in 1888. She was responsible for cataloging stellar spectra for stars in the northern hemisphere. Maury, however, had an interest in theoretical work, something Pickering discouraged in his computers. This strained the relationship between Maury and Pickering, resulting in her intermittent employment during her years at Harvard College Observatory. Dorrit Hoffleit, one of Maury’s colleagues at Harvard College Observatory wrote, “She was one of the most original thinkers of all the women Pickering employed; but instead of encouraging her attempts at interpreting observations, he was only irritated by her independence and departure from assigned and expected routine.”

Maury rearranged Fleming’s spectral scheme to reflect the temperatures of stars. She further refined the sequence by adding another dimension to describe the spectral lines using small case letters. Maury firmly believed that the ‘c-characteristic’ in her system represented a fundamental property of the stars. Other astronomers agreed. In 1905, famed Danish astronomer Ejnar Hertzsprung published his work on stellar magnitudes and luminosities. His “red giant” objects turned out to be the same stars Maury had cataloged with the ‘c-characteristic.’ According to Hertzsprung the separation of the c- and ac- stars by Antonia Maury was the most important advancement in stellar classification since Secchi.

Maury did not complete her work at Harvard College Observatory, leaving in 1891 to pursue a position at Gilman School in Cambridge, Massachusetts. She returned in 1893 for one year, and again in December 1895 to assist with the final phase in the Draper project. The Henry Draper Catalogue was finally published in 1897.

After the completion of the catalogue, Maury lectured on astronomy to professionals in the field, as well as the public. She co-discovered the first spectroscopic binaries, Mizar in Ursa Major, and Beta Aurigae, and was also the first to calculate their orbits. The famous astronomer, John Herschel called her work on spectroscopic binaries “one of the most notable advances in physical astronomy ever made.”

Maury retired from Harvard College Observatory in 1935. She continued to visit Harvard College Observatory to check on observations of her final project, the enigmatic star, Beta Lyrae, until her death in 1952.

Henrietta Swan Leavitt was born on July 4, 1868 in Lancaster, Massachusetts. Leavitt attended Oberlin College and in 1892 graduated from the Society for the Collegiate Instruction for Women, now known as Radcliffe College. Leavitt’s interest in astronomy began during her senior year in college when she took an astronomy class. She furthered her studies in astronomy with graduate work.

Three years after graduation, she became a volunteer research assistant at Harvard College Observatory. Seven years later, in 1902, Pickering hired her on the permanent staff at $.30 per hour. She was given the position of chief of the photographic photometry department and was responsible for the care of telescopes. Leavitt worked sporadically during her time at Harvard, often sidelined by health problems and family obligations. An illness contracted after her graduation from Radcliffe rendered her increasingly deaf.

Leavitt performed research from the observatory’s photographic plate collection. Using these plates, she was charged with determining the brightness of stars in the images. There was no existing standard for ascertaining stellar magnitudes at the time, so Leavitt devised her own system, called “the north polar sequence”. Recognized by the scientific community as an important standard, it was adopted by the International Committee on Photographic Magnitudes in 1913.

Another area of research that Leavitt pursued was variable stars. During her lifetime, she discovered over 1,200 variable stars, half the number of all known variables at the time of her death. In 1908, she made her most important discovery while studying Cepheid variables in the Magellanic Clouds. Leavitt determined that there is a relationship between a Cepheid variable's luminosity and its pulsation period. This period-luminosity relationship is very precise, making Cepheids important standard candles and the foundation of the Cosmological Distance Scale.

Leavitt was a member of Phi Beta Kappa, the American Association of University Women, the American Astronomical and Astrophysical Society, the American Association for the Advancement of Science, and an honorary member of the American Association of Variable Star Observers.

She died on December 21, 1921 from cancer.

Annie Jump Cannon was born in Dover, Delaware in 1863. Her interest in astronomy grew from excursions with her mother who taught her the constellations. Cannon graduated from Wellesley College in 1884 where she studied physics and astronomy under professor Sara Whiting.

For the next eleven years, Cannon studied music and traveled. It was during this time, after a bout of scarlet fever, that she lost her hearing. Upon the death of her mother, she decided to pursue her interests in astronomy full time and went to Radcliffe College as a “special student” for two years. Edwin Pickering was instrumental in her obtaining this special status. In 1896, she joined the ranks of computers at Harvard College Observatory.

Cannon’s duties included cataloging variable stars and classifying the spectra of stars in the southern hemisphere for the Henry Draper Catalogue project, the counterpart to Maury with the northern hemisphere. In her free time, Cannon poured over the observatory’s photographic plate collection, studying variable stars.

Cannon was recognized as the leading expert in identifying and classifying stars, with incredible accuracy and speed. By the time of her death, she had classified up to 350,000 stars, at a rate of up to 300 per hour.

Cannon refined the spectral classification schemes of her predecessors, Fleming and Maury. She reduced the number of categories and arranged them by temperature, from high to low, leaving us with the familiar OBAFGKM. Cannon used numbers from 1-10 to reflect gradation within each category. Her category scheme was so “user-friendly,” it was officially adopted as the standard in 1910 by the International Astronomical Union. Today, with only minor changes, Cannon’s system is known as the Harvard Spectral Classification.

She took over the duties as Curator of Astronomical Photographs when Fleming died in 1911. Cannon also published several volumes of catalogs, including her “Provisional Catalogue” in 1903, with a revision in 1907 listing 1,957 variable stars and their discoverers, the most complete list of its kind at the time. She also revised the Henry Draper Catalogue down to 8th magnitude, published in sections between 1918 and 1924.

Cannon received six honorary degrees, one from Oxford University, the first given to a woman, and was the first woman to receive the Draper Gold Medal. She also established an award to recognize contributions to astronomy by women. She is one of the founding charter members of the American Association of Variable Star Observers.

Cannon worked at Harvard College Observatory for 45 years, until her death at age 77.

It's Always Clear During Full Moon

2010-05-25T15:01:00.002-04:00

There, I said it. We've all said it before, cursing the moon under our breath. "Why couldn't it be clear last week, during the meteor shower, or last month for the eclipse?" Now, when we are least inspired to head out to the telescope for the night because of the big, bright, full moon, NOW it clears up!

After it happens to you so many times it begins to feel like it happens every month. I'm just saying, it feels like it.

To be honest, I've had a pretty good string of clear nights lately, so I have no reason to complain just because it continues to remain clear here. It all started when I brought home the new German equatorial mount for my telescope. Last time I checked in here, I was on my way to NEAF to give a workshop on variable stars and the AAVSO. I've been incredibly busy since then, but that's another story. But, certainly part of that story is the new mount and the clear skies that I've been blessed with.

Now everyone knows you don't buy new astronomy gear and then plan to observe right away. Invariably, as soon as you take your new toy out of the box it gets cloudy for 30 days. It's another well know astronomical urban legend, clouds always come with new gear. That's because they pack them in the box! Everyone knows that.

There may actually be something to that old saying. You see, when I bought my new mount at NEAF this year I didn't have room to bring home the boxes the mount came in. They were way too big for the car we were driving. No way was our luggage and that beast in three boxes fitting in the car. So I opted to bring home the goods boxless. It's been clear or partly cloudy almost every night since, so there is your proof. The clouds come in the box. I didn't bring home the box, therefore, no clouds. As further proof, the weather in New York has not been great since I left. Sorry, New York, I left you my quota of new equipment clouds when I left the boxes behind. Maybe next month it will clear up...probably right around full moon.

Not enough hours in the week

2010-04-13T17:27:00.002-04:00

I could have worse problems than being too busy. So I'm not complaining about the way things have been going lately. I'm working on some really exciting projects for the AAVSO, my research is starting to show results and I've got some traveling to do which started last week and continues into June. Unfortunately, when it gets this crazy the first thing that suffers is usually my blog. I'm sorry if you've already read the Ophiuchus piece and you keep coming here expecting to find some new Simostuff. So, as a way of explaining that it's not me being lazy, let me tell you what I've been up to.

The first, and biggest thing on my plate is writing a proposal for a project which will be the first of its kind ever, and is such a cool idea I wish I'd thought of it- a decadal survey of amateur astronomy and astrophysics. So, what is a decadal survey you ask?

Every ten years, professional astronomers and scientists engage in a two year process to determine what the current state of our knowledge of the universe is, the pressing science questions for the coming decade, and how we should invest billions of tax-payer dollars on satellites, telescopes and other experiments in order to learn the answers to these questions. At the end of the process a summary report, published by the National Academy of Sciences is issued, prioritizing what programs and major initiatives the astronomical community believes show the most promise for advancing the frontiers of human knowledge and offer the maximum scientific return on investment.

This report, the Decadal Survey of Astronomy and Astrophysics, forms the basis for funding decisions made in the following years by NASA, the National Science Foundation and the Department of Defense. The recommendations of this report have resulted in the Hubble, Chandra and Spitzer Space Telescopes, the Wilkinson Microwave Anisotropy Probe (WMAP) and its follow on experiment the Planck Surveyor, the Kepler Mission to find earthlike extra-solar planets, the Expanded Very Large Array (EVLA) and the recently launched Solar Dynamics Observatory (SDO).

We believe it is time to examine the role amateur astronomers, in collaboration with the professional community, can play in the advancement of human knowledge in the coming decade, and propose to undertake a similar initiative, the first of its kind- The International Decadal Survey of Amateur Astronomy and Astrophysics. The goal of this decadal survey will be to carry out an assessment of professional-amateur collaborations in astronomy and astrophysics, and to prepare a concise report, recommending specific projects and areas of scientifically fruitful pro-am collaborations and studies, addressed to professional and amateur astronomical organizations, agencies supporting the field, the governmental committees with jurisdiction over those agencies, the general scientific community, and the public at large.

As project manager, this will probably take up about 20-25% of my time for the next two years, but I think it is so exciting I'm actually looking forward to it. Besides writing a proposal to fund this project, I've been busy writing and talking to people to get letters of support and to gauge their interest and potential to participate in the survey. I've built a website to explain how it will be organized and the time table it will proceed on. You can see it here. Things are progressing nicely, but it is a lot of work.

The Society for Astronomical Sciences (SAS) will be holding their annual symposium in May and I am giving a talk on my Z Cam research, co-authoring on a paper about the decadal survey, and I'm presenting a poster on Photometrica and AAVSOnet.

So, first the research. Z Camelopardalis-type stars (Z Cams or UGZ) are dwarf novae that show cyclic outbursts, but sometimes after an outburst they do not return to their quiescent magnitude. Instead they appear to get stuck, for months or even years, at a brightness of about one magnitude fainter than outburst maximum. These episodes are known as standstills. Z Cam cycle times characteristically range from 10 to 40 days, and their outburst amplitudes are from 2 to 5 magnitudes in V, but standstills are the defining characteristic of the Z Cam stars. Only Z Cams show standstills, so if it doesn't have standstills it isn't a Z Cam.

Above is the light curve for AH Herculis. You can see the up and down light curve where it goes into outburst (gets bright) and then fades back down to 14th magnitude, only to start up again several days later. You can also see the standstill it has been in since last summer on the right. It is stuck around 12.5 mag. It doesn't get bright and it doesn't fade. Standstill.

There are about 50 or so stars that have at one time or another been classified as Z Cam dwarf novae. I argue that the actual number of Z Cams is far less; maybe a dozen or twenty. If I'm right, Z Cams are a rare and interesting type of variable star that has been largely ignored by astronomers up to now. I am coordinating a campaign through the AAVSO CV Section called the Z CamPaign. We've been collecting data on these stars for about 200 days, and I've been examining the light curves of all the known or suspected Z Cams in the AAVSO database, and we've already concluded that several stars long thought to be Z Cams are not, discovered a new phenomena that no one has seen before in two Z Cam stars, and discovered a completely new member of the class. The first paper is written and we're off and running.

Getting Photometrica launched as an online tool for AAVSO members to perform photometry on their CCD images was another project that has recently come to pass. Photometrica is software that exists in a cloud environment. AAVSO doesn't need to buy servers, the software and data storage are hosted by Amazon in their computing cloud. If we need more server capacity, we just pay for more. No maintenance, no hardware, nothing- it just is. So now a member of the AAVSO doesn't need a telescope, CCD, expensive software, or gobs of hard disk storage for images. You can collect data with first class telescopes, the images are automatically uploaded to Photometrica, you log into your account through AAVSO, perform your photometry on the images, generate a report, upload it to the AAVSO database and all you need is internet access. You could literally do this from your IPhone. It's a new world people. One of the dreams is to make this so cheap we can literally give away time and access to developing countries to tech their kids math, science and astronomy.

Speaking of outreach, that leads to my other 'next big thing' on the agenda. I am giving a workshop on variable stars and observing at the North East Astronomy Forum (NEAF) Sunday, April 18, 2010. I am still developing the workshop and working on the presentation. As part of this trip I also had to develop a self-cycling PowerPoint that we can display at our table at NEAF, running from a netbook, projected onto a screen about four feet away in bright lighting. That was a bit of a challenge, but its done. Irene and I leave Friday.

So along with all the regular stuff I have to do every week, there has been a whole new pile of exciting and interesting projects to keep me away from the blog temporarily. But I promise to be back soon. There is no shortage of ideas for articles here either! At last count there were about twenty articles in the drafts folder; mostly pieces I haven't had time to finish because other things took priority. There just aren't enough hours in the week to do it all. But like I said, I could have worse problems.