Thursday, January 06, 2011

Happy 100th birthday to the AAVSO!

Welcome back to a new year (and technically a new decade, though I celebrated that a year early)!  All of us on this celestial ball have just started a new revolution about the Sun (technically the center of mass of the Solar System, which is close to the Sun, but that's not important for most people), so we tend to look forward to a new year full of possibilities and discoveries yet unwritten (or half-written, in my case, but that's another column).

I've blogged many times about the important contributions that non-career astronomers have made and continue to make to the science of astronomy.  Just earlier this week a 10-year old Canadian student, Kathryn Gray, became the youngest known person to help discover a supernova (exploding star). 

One of the largest organizations of citizen astronomers is the American Association of Variable Star Observers, or AAVSO.  The AAVSO was organized in 1911, which makes this year their (let's see, subtract 1911 from 2011, borrow 1 from the thousands column....) centennial!  100 years!  That's no small accomplishment, and the organization is only continuing to grow in membership and impact.

Members of the AAVSO participate in science by monitoring the brightnesses of stars.  Many stars change their brightness, hence the term "variable".  The reasons for these variations are many.  Some stars are really close pairs of stars that periodically eclipse each other.  Some stars grow and shrink in radius due to an unstable structure.  Some stars are pulling material off their companions.  And some stars have planets that occasionally block a tiny amount of light of their parent star. 

The most important tool needed to study variable stars is time.  While many variable stars change their brightnesses in predictable fashion, many others are unpredictable.  And professional telescopes have too many varied research projects to sit and stare at a star that may do nothing for months, years, or even decades before it does something interesting.  The total membership of the AAVSO does have the time and telescope power to watch these stars and notify the big telescopes when something unexpected happens.

But the AAVSO does much, much more than simply act as night watchmen for professional astronomers.  Their measurements of star brightness are often just as accurate, and in some cases better, than those obtained by professional astronomers.  AAVSO members and their data regularly appear in scientific papers.  They are discovering hitherto unknown planets around other stars.  They are discovering changes in variable stars that professionals would never have noticed.  This is all cutting edge science.

You do not need to have a degree in astrophysics to participate in the AAVSO.  You don't even need to have thousands of dollars worth of equipment.  You just need an interest in astronomy, a willingness to learn how to make astronomical measurements, and dedication to looking up at the sky.  Why not stop by the AAVSO website, read about their centennial celebration and their history, and see if any of their ongoing projects tickles your fancy.  There's no reason you can't discover a supernova or a planet yourself!

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