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-
  • 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?
There will be a coordinated observing campaign involving the public, using unaided eye, binoculars, telescopes, digital cameras and CCDs, to measure and archive the data. There will be discussion forums, scientific advisers, training, workshops, real-time feedback- in the form of being able to see your observations displayed as distinct points in the up-to-the-minute light curve, and in the end all this will be turned into projects encouraging and assisting people in writing and submitting scientific papers to a refereed journal. The participants have the real opportunity to become "citizen scientists" indeed.

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.

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