Algol III (2007)
Algol, also known as Beta Persei in the constellation Perseus, is the prototype of a
class of interacting binary stars which differ from cataclysmic binaries. It was the
first eclipsing binary ever found. Viewed from Earth, Algol varies its brightness
over a period of 2.9 days, with the changes caused by a a pair of stars periodically
passing in front of each other and so cutting out the other's light. The larger of
the two stars is losing material to its small companion, the gas forming a tenuous
disc around the smaller star.
