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

Mark VandeWettering makes telescopes, and has written a set of guides for those who would like to build their own. Francis O'Reilly has made a similar set of guides, except as a series of videos.
posted by Upton O'Good on Jun 4, 2008 - 13 comments

"Naked Eye" Comet Machholz (binoculars recommended) nears maximum brightness in the coming days ( starchart here and here). How to photograph a comet and other objects. The story of its discovery (his 10th). Comet hunters are an interesting breed. Now you can discover comets from your 'puter with SOHO imagery. If stargazing interests you, you may also like the Wunderground astronomy web application (based on U.S. zip codes).
posted by spock on Jan 4, 2005 - 7 comments