Once every 27 years or so, the mysterious binary star system of
Epsilon Aurigae undergoes an eclipse, lasting nearly two years. This gives this system the distinction of having both the longest eclipse and the longest period of any known binary system. However, it is not clear why the eclipses last so long, or even what the structure of the system actually looks like--
the main star is a supergiant, with a radius as big as the distance from the earth to the sun, and yet its light is dimmed for two years by something yet bigger. The next eclipse is due to begin in August of 2009, and as part of the
International Year of Astronomy in 2009, amateur astronomers are being called on to make their own observations of the changing brightness of Epsilon Aurigae. If you want to try it yourself, you can read the
training guide to find out how to do your own observations and report them. In addition, the two scientists who organized observations of the previous eclipse both have webpages [
1,
2] which are coordinating the organization for the upcoming observation. If you want to learn more about the science behind ε Aurigae, a good rundown with links to papers is available
here.
posted by Upton O'Good
on Jan 8, 2009 -
32 comments
