When I get asked this question in an interview, on a plane, talking to a potential donor, heck, even when I'm doing a presentation and can take as much time as I want, I rarely get to answer the question to my satisfaction. There is always the lingering feeling that I left something important out, or that I could have worded it better for that particular audience or listener.
It happened again last Friday on SLOOH Radio. We were kinda jumping around from topic to topic when the question finally came up. I had to back track a little and then try to answer the question as succinctly as possible, relating to what we had already discussed and hinting at the interesting topics to come.
I suppose it all turned out alright in the end. The hosts, Marty and Mike, asked me to come again and took me to their favorite pub after for dinner and drinks, so it must not have sucked.
So, what are variable stars?
Here is what I wish I'd said.
Variable stars are stars that vary in brightness on timescales ranging from seconds to centuries. Astronomers find them interesting because many of the changes that are occurring give us information about the distance, mass, size, age and composition of these stars. They have and continue to provide us with important clues about the life cycle of stars. Some vary because they are young and unsettled. Some vary because they are middle aged and going through changes in their interiors. Some represent the end stages, or old age of stars, and some are the brilliant cataclysmic destruction of a star that spews its guts out into space seeding the next generation of stars and planets with material from which to build.
Some variable stars vary so minutely that it takes specialized, highly calibrated instruments to detect the changes. Some vary so greatly that occasionally a star only visible in a telescope becomes the brightest star in the sky, visible to the unaided eye for weeks or months. The light from some stars varies because it is being eclipsed by a planet transiting in front of it from our point of view.
Even more bizarre, some things that look like stars and vary like variable stars are not stars at all! They are the light being given off as super-massive black holes at the heart of distant galaxies devour the gas and stars around them.
In spite of all our technological advancement, the study of variable stars is still one area of science where amateurs can and do make valuable contributions to science.
And that is where I will begin to explain what the AAVSO is all about.
I hope I can remember all this, for the next person who asks me on a plane...
Professional and Amateur Collaboration
Amateur astronomers and the American Association of Variable Star Observers (AAVSO) have done it again. This time AAVSO observers were able to provide timely observations to alert UK radio astronomers of the early stages of an outburst of SS Cygni. The results, the first ever detection of a radio jet from a dwarf nova, have been published in the journal Science. The pre-print of the paper can be downloaded from arXiv.org.
What I found most intriguing about this paper is that the jets they were looking for were transient phenomena that only occur at a certain stage of the outburst (onset). The astronomers predicted that the jets would exist, and at which stage of the outburst they would be detectable _before_ observing them. This brought to mind a comment Joe Patterson made in an interview for CVnet we did a couple years ago. "The dwarf-nova outburst itself has become generally well understood -- in the sense that there's a theory which successfully reproduces the observed phenomena. But it's noteworthy that all of that theory was crafted to fit previously known data -- it has never actually predicted something not known in advance."
Congratulations to Dr. Elmar Koerding and his team for their discovery, and kudos to the amateur variable star observers all over the world who made this observation possible. There is a very nice optical and radio light curve of the outburst on page 6 of the paper. Multi-million dollar radio telescope observations coupled with visual observations from backyard telescopes, the very definition of pro-am collaboration.
What I found most intriguing about this paper is that the jets they were looking for were transient phenomena that only occur at a certain stage of the outburst (onset). The astronomers predicted that the jets would exist, and at which stage of the outburst they would be detectable _before_ observing them. This brought to mind a comment Joe Patterson made in an interview for CVnet we did a couple years ago. "The dwarf-nova outburst itself has become generally well understood -- in the sense that there's a theory which successfully reproduces the observed phenomena. But it's noteworthy that all of that theory was crafted to fit previously known data -- it has never actually predicted something not known in advance."
Congratulations to Dr. Elmar Koerding and his team for their discovery, and kudos to the amateur variable star observers all over the world who made this observation possible. There is a very nice optical and radio light curve of the outburst on page 6 of the paper. Multi-million dollar radio telescope observations coupled with visual observations from backyard telescopes, the very definition of pro-am collaboration.
Robots From Mars
Ice, schmice. Everyone's talking about ice on Mars.
Hullo! I've seen the polar ice caps on Mars a hundred times through my telescope. Big deal.
While everyone else blogs, comments and debates "is it water ice or not?" I decided to go Simosurfing.
It's amazing how far down the hole you can crawl when searching/researching on the web. Sometimes I look at the clock on the wall and think "It took me two hours and THIS is where I landed?"
Then again, occasionally you find a gem that makes you smile and it was worth the treasure hunt. Believe it or not, I found this on Tommy Lee's MySpace page (don't ask...)
It's from 'Robots From Mars'-
"OPEN LETTER TO NASA
Dear NASA,
Please stay on your own planet!
We are sorry to say that we watched the Phoenix’s successful landing on Mars.
Why are you here?
We would like to know if this Peeping Tom behavior will ever end?
Do we spy on you? Well…that’s another story.
PS You’ll never locate your first Polar Lander.
It was just yummy.
It is hard to describe the succulent taste of rare Earth metals.
Please send more wreckage!
PPS A kindly reminder from the Robots From Mars…
The First Law of Robotics only applies to synthetic beings of Earthly origin."
I think Robots From Mars is a rock band, but I wasn't willing to invest the time on their pages to find out. Just thought I'd share.
Hullo! I've seen the polar ice caps on Mars a hundred times through my telescope. Big deal.
While everyone else blogs, comments and debates "is it water ice or not?" I decided to go Simosurfing.
It's amazing how far down the hole you can crawl when searching/researching on the web. Sometimes I look at the clock on the wall and think "It took me two hours and THIS is where I landed?"
Then again, occasionally you find a gem that makes you smile and it was worth the treasure hunt. Believe it or not, I found this on Tommy Lee's MySpace page (don't ask...)
It's from 'Robots From Mars'-
"OPEN LETTER TO NASA
Dear NASA,
Please stay on your own planet!
We are sorry to say that we watched the Phoenix’s successful landing on Mars.
Why are you here?
We would like to know if this Peeping Tom behavior will ever end?
Do we spy on you? Well…that’s another story.
PS You’ll never locate your first Polar Lander.
It was just yummy.
It is hard to describe the succulent taste of rare Earth metals.
Please send more wreckage!
PPS A kindly reminder from the Robots From Mars…
The First Law of Robotics only applies to synthetic beings of Earthly origin."
I think Robots From Mars is a rock band, but I wasn't willing to invest the time on their pages to find out. Just thought I'd share.
Astronomical Paranoia
Everybody scoops me. I don't try that hard to be the first one to bring you breaking news on my blog. Some bloggers get all wrapped up in breaking news and end up missing the more important story or the eventual truth revealed. I prefer to watch things develop, get a feel for where they are heading, and then add my own perspective once I've had time to think about it. Think of my blog as the follow up to breaking stories that you seldom get in print and NEVER get on television as they race to scoop the other guy and retain market share.
Getting scooped by a competitor and the accompanying paranoia has a long history in astronomy too. One case that comes immediately to mind is the prediction and discovery of the planet Neptune. In 1845 Urban Jean Joseph Le Verrier presented a paper to the Paris Academy of Sciences explaining why Uranus was not following the rules of Newtonian mechanics as seen from Earth. The following summer he presented a second paper concluding that there was an 8th planet and described its longitude in relation to the sun within a few degrees.
Meanwhile, in England, John Couch Adams was working on the same problem, and derived an approximate solution by October 1843. Unfortunately, his more precise results did not reach the Astronomer Royal, George Biddel Airy, at Greenwich until October 1845. Upon seeing Le Verrier's nearly identical results Airy convinced astronomers at the Cambridge Observatory to search for the undiscovered planet, but they had such poor charts of that area of the sky that the search proceeded very slowly.
Le Verrier had convinced astronomers at the Berlin Observatory to undertake a search program. Armed with their new Star Atlas they began their search on September 26, 1846. That same night they found a 'star' that was not in their atlas. It was Neptune. The British suggestion that Adams be given partial credit for the discovery was ridiculed severely in Paris papers.
Earlier in history, Galileo, aware of competition as the telescope was becoming available to more observers, resorted to writing up his discoveries in the form of anagrams. That way he could claim first 'publication' without giving away what he had found exactly. Of course, if he turned out to be wrong there was no need to translate the anagram!
When writing about the discovery of the phases of Venus, Galileo resorted to encoding the discovery in a Latin anagram, which when decoded and translated declares that Venus imitates the phases of the Moon. After observing the rings of Saturn for the first time he circulated a jumble of nonsense that later would be translated to “I have observed the highest planet tri-form.”
Christiaan Huygens, upon publishing the discovery of Saturn's moon Titan also circulated an anagram describing his discovery of the actual nature of Saturn's rings. A few years later he was still able to claim to be the first to realize that the tri-planet was actually a ring system, since the anagram predated any other discovery announcements.
Modern times and scientific enlightenment has changed nothing. With astronomers competing for telescope time and funding, the drive to be first is still very alive and well. Often times, several teams of astronomers will be working on the same problem or similar projects that overlap in scope. And so we come to today's real topic.
On the Systemic website, Dr. Greg Laughlin has announced a discovery in the tradition of Galileo and Huygens in the form of an anagram. It reads, "Huge Applet, Unsearchable Terrestrials". Predictions as to what this actually means have filled up the comments section to blogs. Since posting the anagram last month, Laughlin has given several more clues: it contains a German name, and doesn’t contain the words “super” and “Earth.” The best guesses seem to be something to do with an earth-like planet around a star named Gliese something or another.
I can't blame the guy. Almost exactly one year ago he and his team were scooped by a Swiss team that discovered a Neptune sized planet orbiting Gleise 436. He even recounts the story of Adams and Le Verrier on his blog site, bemoaning his hard learned lesson about getting timely follow-up data.
Stay tuned. When the true nature of the discovery is finally announced, it won't be breaking news, since it's already been announced, we just can't translate it! But I promise I'll let you all in on the big secret when it comes out.
Getting scooped by a competitor and the accompanying paranoia has a long history in astronomy too. One case that comes immediately to mind is the prediction and discovery of the planet Neptune. In 1845 Urban Jean Joseph Le Verrier presented a paper to the Paris Academy of Sciences explaining why Uranus was not following the rules of Newtonian mechanics as seen from Earth. The following summer he presented a second paper concluding that there was an 8th planet and described its longitude in relation to the sun within a few degrees.
Meanwhile, in England, John Couch Adams was working on the same problem, and derived an approximate solution by October 1843. Unfortunately, his more precise results did not reach the Astronomer Royal, George Biddel Airy, at Greenwich until October 1845. Upon seeing Le Verrier's nearly identical results Airy convinced astronomers at the Cambridge Observatory to search for the undiscovered planet, but they had such poor charts of that area of the sky that the search proceeded very slowly.
Le Verrier had convinced astronomers at the Berlin Observatory to undertake a search program. Armed with their new Star Atlas they began their search on September 26, 1846. That same night they found a 'star' that was not in their atlas. It was Neptune. The British suggestion that Adams be given partial credit for the discovery was ridiculed severely in Paris papers.
Earlier in history, Galileo, aware of competition as the telescope was becoming available to more observers, resorted to writing up his discoveries in the form of anagrams. That way he could claim first 'publication' without giving away what he had found exactly. Of course, if he turned out to be wrong there was no need to translate the anagram!
When writing about the discovery of the phases of Venus, Galileo resorted to encoding the discovery in a Latin anagram, which when decoded and translated declares that Venus imitates the phases of the Moon. After observing the rings of Saturn for the first time he circulated a jumble of nonsense that later would be translated to “I have observed the highest planet tri-form.”
Christiaan Huygens, upon publishing the discovery of Saturn's moon Titan also circulated an anagram describing his discovery of the actual nature of Saturn's rings. A few years later he was still able to claim to be the first to realize that the tri-planet was actually a ring system, since the anagram predated any other discovery announcements.
Modern times and scientific enlightenment has changed nothing. With astronomers competing for telescope time and funding, the drive to be first is still very alive and well. Often times, several teams of astronomers will be working on the same problem or similar projects that overlap in scope. And so we come to today's real topic.
On the Systemic website, Dr. Greg Laughlin has announced a discovery in the tradition of Galileo and Huygens in the form of an anagram. It reads, "Huge Applet, Unsearchable Terrestrials". Predictions as to what this actually means have filled up the comments section to blogs. Since posting the anagram last month, Laughlin has given several more clues: it contains a German name, and doesn’t contain the words “super” and “Earth.” The best guesses seem to be something to do with an earth-like planet around a star named Gliese something or another.
I can't blame the guy. Almost exactly one year ago he and his team were scooped by a Swiss team that discovered a Neptune sized planet orbiting Gleise 436. He even recounts the story of Adams and Le Verrier on his blog site, bemoaning his hard learned lesson about getting timely follow-up data.
Stay tuned. When the true nature of the discovery is finally announced, it won't be breaking news, since it's already been announced, we just can't translate it! But I promise I'll let you all in on the big secret when it comes out.
Sex in Space
This came across the UPI wire last week.
"Virgin Galactic, a New Mexico space tourism company, said it has received several requests from couples seeking to be the first to have sex in space."
This is a mind bending sentence. There are at least two concepts here that were strictly science fiction not so long ago.
First, the concept of a space tourism company. I'm sure you've all heard suggestions of this happening eventually, but Virgin Galactic is planning it's first 'space flight' in 2009. The future is here folks. We will have ordinary (albeit very rich) people flying into space in our lifetime.
Knowing this is about to happen, several couples have contacted Virgin Galactic representatives inquiring about sex in space, and one couple wants to book a charter flight so they can be the first couple to have intercourse in space and get into the Guinness Book of Records.
I find it staggering how easily we can skip over the seemingly mundane concept of a 'space tourism company' and jump right into the idea of humans having sex in space. But now that we are here, let's talk about what sex in space might be like.
Whatever it's like for the first couple, I can tell you it's going to be brief. The weightless portion of the first Virgin Galactic space flight will only last about five minutes. That's not going to count for much in my record book, but hey, you work with what you've got.
Eventually, there will be much longer flights and space hotels. Bigelow Aerospace envisions putting a hotel complex in orbit where people will be "recreating and having sex" within the next decade.
So what will sex in space be like? "The fantasy might be vastly superior to the reality," says NASA physician Jim Logan.
Sex will likely be hotter in space. There is no natural convection to carry away body heat in zero gravity. People also tend to perspire more in zero-G. The moisture generated while in the act could begin to pool into floating droplets of well, 'stuff'.
The lower blood pressure that humans experience in zero-G is not going to be very helpful to the men. Add the common effects of motion sickness to the equation and the reality of sex in space may be summed up in those famous words, "Houston, we have a problem."
Even assuming 'all conditions are go' choreographing sex will present all kinds of challenges. Remember, every action has an opposite and equal reaction. Lovers will need to be anchored to the floor, walls or each other to stay connected. To this end, special clothing is being designed, equipped with strategically placed Velcro strips and zippers. Honest, I couldn't even make this stuff up, but there are people out there planning for it!
Personally, I'm not interested in being the first. Five minutes just isn't long enough. But to have hot, wet, messy sex, floating weightlessly, while wearing Velcro straps and zippers sounds pretty wild. Where do I sign up?
"Virgin Galactic, a New Mexico space tourism company, said it has received several requests from couples seeking to be the first to have sex in space."
This is a mind bending sentence. There are at least two concepts here that were strictly science fiction not so long ago.
First, the concept of a space tourism company. I'm sure you've all heard suggestions of this happening eventually, but Virgin Galactic is planning it's first 'space flight' in 2009. The future is here folks. We will have ordinary (albeit very rich) people flying into space in our lifetime.
Knowing this is about to happen, several couples have contacted Virgin Galactic representatives inquiring about sex in space, and one couple wants to book a charter flight so they can be the first couple to have intercourse in space and get into the Guinness Book of Records.
I find it staggering how easily we can skip over the seemingly mundane concept of a 'space tourism company' and jump right into the idea of humans having sex in space. But now that we are here, let's talk about what sex in space might be like.
Whatever it's like for the first couple, I can tell you it's going to be brief. The weightless portion of the first Virgin Galactic space flight will only last about five minutes. That's not going to count for much in my record book, but hey, you work with what you've got.
Eventually, there will be much longer flights and space hotels. Bigelow Aerospace envisions putting a hotel complex in orbit where people will be "recreating and having sex" within the next decade.
So what will sex in space be like? "The fantasy might be vastly superior to the reality," says NASA physician Jim Logan.
Sex will likely be hotter in space. There is no natural convection to carry away body heat in zero gravity. People also tend to perspire more in zero-G. The moisture generated while in the act could begin to pool into floating droplets of well, 'stuff'.
The lower blood pressure that humans experience in zero-G is not going to be very helpful to the men. Add the common effects of motion sickness to the equation and the reality of sex in space may be summed up in those famous words, "Houston, we have a problem."
Even assuming 'all conditions are go' choreographing sex will present all kinds of challenges. Remember, every action has an opposite and equal reaction. Lovers will need to be anchored to the floor, walls or each other to stay connected. To this end, special clothing is being designed, equipped with strategically placed Velcro strips and zippers. Honest, I couldn't even make this stuff up, but there are people out there planning for it!
Personally, I'm not interested in being the first. Five minutes just isn't long enough. But to have hot, wet, messy sex, floating weightlessly, while wearing Velcro straps and zippers sounds pretty wild. Where do I sign up?
Plutoids
It seems the IAU is trying to make the public a little happier about demoting Pluto from planetary status. They have invented and adopted a new term to describe Pluto and its brethren, "Plutoids".
According to the new definition, plutoids are celestial bodies in orbit around the Sun at a distance greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighborhood around their orbit. The two known and named plutoids are Pluto and Eris. It is expected that more plutoids will be named as science progresses and new discoveries are made.
The saddest part of this news really affects Ceres, formerly an asteroid, a minor planet and now dwarf planet. Even though it is very similar to Pluto and Eris, it does not fit the definition of a plutoid because it is located in the asteroid belt between Mars and Jupiter. Not only that, but since we don't believe any more Ceres sized objects exist inside the orbit of Neptune (presumably, we would have already discovered them) there are no plans to propose a new name for these type objects.
So, we have adopted a new term for objects we believe will be commonplace one day, but have no special term for the one and only dwarf planet that has survived billions of years in the asteroid belt. Poor Ceres. I guess no one takes you cereously...
According to the new definition, plutoids are celestial bodies in orbit around the Sun at a distance greater than that of Neptune that have sufficient mass for their self-gravity to overcome rigid body forces so that they assume a hydrostatic equilibrium (near-spherical) shape, and that have not cleared the neighborhood around their orbit. The two known and named plutoids are Pluto and Eris. It is expected that more plutoids will be named as science progresses and new discoveries are made.
The saddest part of this news really affects Ceres, formerly an asteroid, a minor planet and now dwarf planet. Even though it is very similar to Pluto and Eris, it does not fit the definition of a plutoid because it is located in the asteroid belt between Mars and Jupiter. Not only that, but since we don't believe any more Ceres sized objects exist inside the orbit of Neptune (presumably, we would have already discovered them) there are no plans to propose a new name for these type objects.
So, we have adopted a new term for objects we believe will be commonplace one day, but have no special term for the one and only dwarf planet that has survived billions of years in the asteroid belt. Poor Ceres. I guess no one takes you cereously...
The Scorpion
My astrological sign is Scorpius. I never really think about it, because I don't believe in astrology. In fact, when people ask me what my sign is I usually tell them, "Caution; rough road ahead".
But the constellation Scorpio is one of the few that actually looks like it's name. It's a beautiful constellation in the heart of the Milky Way. The long curved string of bright stars that curls into the scorpions stinger is unmistakable. From my home in Michigan it's not a very impressive sight. Scorpio barely clears the tops of the trees and the curved tail is usually lost in the haze near the horizon. But from St. John in the Virgin Islands it is awesome. I was strangely proud to be a 'Scorpio' as I pointed it out to my family and friends.
Things look very different from 18 degrees north than they do at +45! Scorpio and Sagittarius ride high in the south, Bootes was straight over head and Polaris is noticeably lower in the north. We stood out on the veranda last night and I gave an astronomy 101 class, explaining the phases of the moon, the ecliptic as the plane of the solar system, and as the Milky Way rose up we talked about the galaxy, dust and gas and the Great Rift, star formation and evolution and the vast distances to even the nearest stars.
There is even a good old fashioned Greek legend about Scorpio killing the great Orion to keep people awake. According to legend, that is why they are segregated to opposite ends of the sky, so it can never happen again.
I stayed up for about an hour after everyone finally called it a night, enjoying the beauty and serenity of it all, and waxing philosophically. My son gets married on the beach at Trunk Bay today, and I was wondering how long it will be before I am standing in the dark, holding the tiny hand of the next generation of Simonsens, describing the wonders of the Universe and telling stories of Greek heroes and scorpions killing great hunters.
But the constellation Scorpio is one of the few that actually looks like it's name. It's a beautiful constellation in the heart of the Milky Way. The long curved string of bright stars that curls into the scorpions stinger is unmistakable. From my home in Michigan it's not a very impressive sight. Scorpio barely clears the tops of the trees and the curved tail is usually lost in the haze near the horizon. But from St. John in the Virgin Islands it is awesome. I was strangely proud to be a 'Scorpio' as I pointed it out to my family and friends.
Things look very different from 18 degrees north than they do at +45! Scorpio and Sagittarius ride high in the south, Bootes was straight over head and Polaris is noticeably lower in the north. We stood out on the veranda last night and I gave an astronomy 101 class, explaining the phases of the moon, the ecliptic as the plane of the solar system, and as the Milky Way rose up we talked about the galaxy, dust and gas and the Great Rift, star formation and evolution and the vast distances to even the nearest stars.
There is even a good old fashioned Greek legend about Scorpio killing the great Orion to keep people awake. According to legend, that is why they are segregated to opposite ends of the sky, so it can never happen again.
I stayed up for about an hour after everyone finally called it a night, enjoying the beauty and serenity of it all, and waxing philosophically. My son gets married on the beach at Trunk Bay today, and I was wondering how long it will be before I am standing in the dark, holding the tiny hand of the next generation of Simonsens, describing the wonders of the Universe and telling stories of Greek heroes and scorpions killing great hunters.
Citizen Scientists
One of the many interesting and exciting programs being developed for the International Year of Astronomy 2009 (IYA) is what is called Research Experiences for Teachers, Students and Citizen Science. I spent the majority of my time at the AAS meeting, before, during and after the sessions, with the people in the working group who are making plans for involving the public in real astronomy research projects.
I admit to being biased when it comes to variable star research, but the project they are working on that involves monitoring the eclipse of epsilon Aurigae is absolutely fascinating.
Now let's get this pronunciation thing out in the open. Auriga the constellation is pronounced aw-RYE-guh. The genitive of the name, Aurigae, is pronounced aw-RYE-gee. If you are a citizen and want to research this, here are some lists that agree, more or less.
Sky and Telescope's page on pronunciations
AOL Hometown page -don't laugh, they got it right.
Aaron B. Clevenson -I never heard of him either, but he speaks the truth, and can pronounce it!
Okay, back to the point. Epsilon Aurigae (eps Aur) is an enigma. Even though it has been known to be an eclipsing variable star for over 150 years, and even though it is bright, easily visible with the unaided eye, we don't know much about its true nature at all.
Part of the problem is the eclipses only happen once every 27 years. You're living right if you get to witness two or three eclipses in a lifetime. Another challenge is the fact that due to its brightness it is not well suited for study by large ground based telescopes or space telescopes. We would blow up the instrument package on Hubble if we pointed it at a 3rd magnitude star! Another mystery arose when we began to study the system spectroscopically. Even though we could categorize the primary, there was no sign of the secondary object in the spectrum. The companion is invisible, yet it eclipses the primary!
What we think we know is that the primary star of the pair is an FO1a supergiant. That is a spectral classification that reveals some characteristics of the star. These stars are typically 8-15 times the mass of the sun. They also sit precariously at the edge of the Cepheid instability strip on the H-R diagram. (Translation: this type of star typically evolves into another type of variable star that pulsates with a period that is proportional to its actual brightness, otherwise known as absolute magnitude). There is some evidence that the primary or something else may actually be varying with some periodicity, but not much is known for certain.
What we don't know could fill pages. Essentially, we do not know what the companion object is that orbits around the primary, periodically eclipsing it and dimming its light as seen from Earth. One popular model suggests it is a flattened disk-like object, perhaps with a hole in the center containing one or more stars, slightly tilted or warped in relation to its orbit.
The list of unknowns is impressive-
Think about that for a moment. You could be involved in writing a paper finally unlocking the secrets of a star that has baffled the likes of Gerard Kuiper, Otto Struve and Bengt Stromgren.
If you'd like to learn more, without having to spend a day and a half of your life Googling everything you've just read here, read the excellent Variable Star of the Season article by Matt Templeton on the AAVSO website.
As if that weren't enough, there are the beginnings of plans to involve 'citizen scientists' in the LCROSS mission. This is a mission something like the Deep Impact mission, where we slammed a spacecraft into comet 9P/Tempel to see what would come out of the blast; or more precisely like the Lunar Prospector mission, where the satellite was deliberately crashed on the moon to look for water ice in permanently shadowed craters. Both experiments caught the public imagination. LCROSS will bomb a permanently shadowed crater at the the moons' south pole to look for ancient ice buried there. Mission scientists estimate the LCROSS impact plume may be visible through amateur telescopes with apertures of 10 to 12 inches.
Although I doubt they will be looking for amateur collaboration writing the science results up for publication, they will be encouraging as many observers as possible to cover the impact. You never know, it might be cloudy in Hawaii that night, and your images with your home-built 20 inch scope and CCD could be the best ground based visual record of the event.
C'mon, this is cool stuff. If you don't think so, shave your head, give away all your earthly belongings (to the AAVSO Endowment) and go shake a tambourine at the airport.
I admit to being biased when it comes to variable star research, but the project they are working on that involves monitoring the eclipse of epsilon Aurigae is absolutely fascinating.
Now let's get this pronunciation thing out in the open. Auriga the constellation is pronounced aw-RYE-guh. The genitive of the name, Aurigae, is pronounced aw-RYE-gee. If you are a citizen and want to research this, here are some lists that agree, more or less.
Sky and Telescope's page on pronunciations
AOL Hometown page -don't laugh, they got it right.
Aaron B. Clevenson -I never heard of him either, but he speaks the truth, and can pronounce it!
Okay, back to the point. Epsilon Aurigae (eps Aur) is an enigma. Even though it has been known to be an eclipsing variable star for over 150 years, and even though it is bright, easily visible with the unaided eye, we don't know much about its true nature at all.
Part of the problem is the eclipses only happen once every 27 years. You're living right if you get to witness two or three eclipses in a lifetime. Another challenge is the fact that due to its brightness it is not well suited for study by large ground based telescopes or space telescopes. We would blow up the instrument package on Hubble if we pointed it at a 3rd magnitude star! Another mystery arose when we began to study the system spectroscopically. Even though we could categorize the primary, there was no sign of the secondary object in the spectrum. The companion is invisible, yet it eclipses the primary!
What we think we know is that the primary star of the pair is an FO1a supergiant. That is a spectral classification that reveals some characteristics of the star. These stars are typically 8-15 times the mass of the sun. They also sit precariously at the edge of the Cepheid instability strip on the H-R diagram. (Translation: this type of star typically evolves into another type of variable star that pulsates with a period that is proportional to its actual brightness, otherwise known as absolute magnitude). There is some evidence that the primary or something else may actually be varying with some periodicity, but not much is known for certain.
What we don't know could fill pages. Essentially, we do not know what the companion object is that orbits around the primary, periodically eclipsing it and dimming its light as seen from Earth. One popular model suggests it is a flattened disk-like object, perhaps with a hole in the center containing one or more stars, slightly tilted or warped in relation to its orbit.
The list of unknowns is impressive-
- How far away is it?
- What is the mass of the system?
- What is the mass of the primary?
- What is the mass of the secondary, whatever it is?
- Is the center of the disk empty?
- If not empty, what is at the center of the disk; one star, two stars, a black hole, something else?
- Will the light curve this time resemble the last eclipse, or will it be different, indicating the system is evolving or changing in some manner?
Think about that for a moment. You could be involved in writing a paper finally unlocking the secrets of a star that has baffled the likes of Gerard Kuiper, Otto Struve and Bengt Stromgren.
If you'd like to learn more, without having to spend a day and a half of your life Googling everything you've just read here, read the excellent Variable Star of the Season article by Matt Templeton on the AAVSO website.
As if that weren't enough, there are the beginnings of plans to involve 'citizen scientists' in the LCROSS mission. This is a mission something like the Deep Impact mission, where we slammed a spacecraft into comet 9P/Tempel to see what would come out of the blast; or more precisely like the Lunar Prospector mission, where the satellite was deliberately crashed on the moon to look for water ice in permanently shadowed craters. Both experiments caught the public imagination. LCROSS will bomb a permanently shadowed crater at the the moons' south pole to look for ancient ice buried there. Mission scientists estimate the LCROSS impact plume may be visible through amateur telescopes with apertures of 10 to 12 inches.
Although I doubt they will be looking for amateur collaboration writing the science results up for publication, they will be encouraging as many observers as possible to cover the impact. You never know, it might be cloudy in Hawaii that night, and your images with your home-built 20 inch scope and CCD could be the best ground based visual record of the event.
C'mon, this is cool stuff. If you don't think so, shave your head, give away all your earthly belongings (to the AAVSO Endowment) and go shake a tambourine at the airport.
Listening to the stars
Once upon a time, I wanted to be a radio astronomer. What is a radio astronomer, someone who talks about astronomy on the radio? No, no, no...although I would probably be good at that!
Radio astronomers observe the universe using big dish antennae, like the Arecibo Radio Telescope in Puerto Rico (upper left), or a more typical dish like the one below, on the right.
At the AAS meeting in St. Louis, I met three young astronomers from West Virginia University who were using radio telescopes to study pulsars, the rapidly spinning remains of exploded supernovae. They had four posters in the display hall and were very gracious explaining what it all meant and answering my neophyte questions.The first paper described how they utilized the Green Bank Radio Telescope in drift scan mode while the tracking was shut down in the summer of 2007. Yup, that's right, the telescope was down for repairs and could only point in one direction on the sky, but they were able to design a program, submit a proposal and get telescope time to do a survey looking for pulsars and transient radio signals. They discovered some new pulsars and stumbled across some known pulsars. They will be doing follow-up observations on the new discoveries to try to determine more accurate astrometric (position) and spin properties.
The second poster discussed how they used a computer simulation program to model pulsars by changing various properties, like the alignment between the spin and magnetic axes, demonstrating the differences and viability of two competing models. I admit, this was way over my head and my brain was spinning at some fraction of a typical pulsar spin period about half way through the explanation. The whole thing is mind boggling, really. We're talking about the properties of extremely dense stellar remnants spinning thousands of times per second!
Another paper described the successes they were having using the Arecibo radio dish to perform the most sensitive large scale survey for pulsars to date. So far they have discovered 35 new pulsars, and based on that figure they predict they will find some 1500 pulsars by the time the survey is complete. Now that is impressive, but what I found even more fascinating is the fact that they are using networks of remote computers, much like SETI@home, to sift through all the terabytes of data and identify new sources.
The other West Virginia U poster described using the Giant Metrewave Radio Telescope in India to study the radio universe in meter wavelengths. Think about that for a second. Light in this part of the spectrum comes to us in waves three feet long or greater! This observatory combines the signals from 30 dishes 45 meters in diameter to "provide a more detailed view of our universe than a single dish of larger size". Combining signals from multiple telescopes like this is known as interferometry. Both optical and radio telescopes are being used in this way. The advantage gained is the ability to distinguish finer detail in celestial objects than is possible with a single mirror or radio dish.
This is the technique used to study things as small as the proto-planetary disks around stars, the subject of an invited talk given by David Wilner at the AAS meeting Tuesday, June 3rd. One of the most remarkable things I saw in this presentation were the actual radio images of disks around other stars in our galaxy. Some of them were irregular shaped, not perfectly round as I had imagined they would be. Even more incredible was the fact that from the radio data the astronomers were able to determine the structure and density to a greater degree than I imagined possible, and some of these disks actually had areas vacated or cleared out as if a planet or other body in orbit around the star had gobbled up the material in its path, like the shepherd moons and gaps in the rings of Saturn.
I don't think they could do anything like this stuff when I was college age, and obviously, I made other career and life choices, but it was nice to get a whiff of what is being done nowadays in a field I may actually have pursued in a parallel dimension.
I think I was born for this
Sometimes life pushes you downstream to a place where you just have to paddle over to the bank and take a longer look, maybe even stay for a while.
Today I've beached the canoe in a new land I've only glimpsed from afar before, Blogs and Podcasts. I've dipped my toe in the water before. I just wasn't very excited at what I found the first few times around; mostly boring people with extreme opinions or boring people with nothing to say.
Then some friends of mine created a podcast called Slacker Astronomy
I wasn't smart enough or tech-savvy enough to see where this was going at the time, but over the past couple years I've caught up a bit. Now I listen to the podcast regularly, at least as often as they actually produce one (they are slackers after all), and I've discovered other excellent astronomy blogs and podcasts I like to visit also, namely Astronomy Cast and Bad Astronomy.
What I find most refreshing and amazing is that these sites actually expose and explain astronomy to the public in an entertaining and exciting new way, and tens of thousands of people are tuning in, downloading and sharing this content every week.
So what lead me to actually create my own blog?
I've just returned from the 212th Meeting of the American Astronomical Society (AAS) in St. Louis, MO. As a part of this meeting within a meeting, the Astronomical Society of the Pacific (ASP) held a symposium on 'Preparing for the International Year of Astronomy'. Most of the papers, talks and discussions I participated in dealt with 'new media' or 'citizen science' projects, and I have to confess, I'm geeked and I want in on the fun.
Do we really need another astronomy blog?
I'm not sure, I hope so.
I think I was born for this.
I love to write, and I'm not shy about sharing my opinions. I've been an avid amateur astronomer since I was a teenager. I'm one of the most prolific variable star observers on the planet and I am now employed by the American Association of Variable Star Observers (AAVSO). I've been writing articles on variable stars for over a decade now for AAVSO, my personal website on variable stars and another site specifically geared towards cataclysmic variables, CVnet. I think I have a unique perspective and voice to bring to the astronomy web round table.
From a more personal standpoint, I've also found that the vast majority of the people I've met through astronomy have been friendly, intelligent, interesting people eager to share what they know and are studying. Perhaps through this blog I'll get to know some more of you and we can double the joy by sharing our study of and amazement at the one cosmic laboratory we all have to play in- the Universe.
Today I've beached the canoe in a new land I've only glimpsed from afar before, Blogs and Podcasts. I've dipped my toe in the water before. I just wasn't very excited at what I found the first few times around; mostly boring people with extreme opinions or boring people with nothing to say.
Then some friends of mine created a podcast called Slacker Astronomy
I wasn't smart enough or tech-savvy enough to see where this was going at the time, but over the past couple years I've caught up a bit. Now I listen to the podcast regularly, at least as often as they actually produce one (they are slackers after all), and I've discovered other excellent astronomy blogs and podcasts I like to visit also, namely Astronomy Cast and Bad Astronomy.
What I find most refreshing and amazing is that these sites actually expose and explain astronomy to the public in an entertaining and exciting new way, and tens of thousands of people are tuning in, downloading and sharing this content every week.
So what lead me to actually create my own blog?
I've just returned from the 212th Meeting of the American Astronomical Society (AAS) in St. Louis, MO. As a part of this meeting within a meeting, the Astronomical Society of the Pacific (ASP) held a symposium on 'Preparing for the International Year of Astronomy'. Most of the papers, talks and discussions I participated in dealt with 'new media' or 'citizen science' projects, and I have to confess, I'm geeked and I want in on the fun.
Do we really need another astronomy blog?
I'm not sure, I hope so.
I think I was born for this.
I love to write, and I'm not shy about sharing my opinions. I've been an avid amateur astronomer since I was a teenager. I'm one of the most prolific variable star observers on the planet and I am now employed by the American Association of Variable Star Observers (AAVSO). I've been writing articles on variable stars for over a decade now for AAVSO, my personal website on variable stars and another site specifically geared towards cataclysmic variables, CVnet. I think I have a unique perspective and voice to bring to the astronomy web round table.
From a more personal standpoint, I've also found that the vast majority of the people I've met through astronomy have been friendly, intelligent, interesting people eager to share what they know and are studying. Perhaps through this blog I'll get to know some more of you and we can double the joy by sharing our study of and amazement at the one cosmic laboratory we all have to play in- the Universe.
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