variable star

Looking toward the eastern horizon on a cool, mid-November evening the Autumn constellations are on prominent display while those of Winter are just starting to rise, and the constellations of Summer are setting in the west. Almost due east is the bright star Capella, in the constellation Auriga. Between Auriga and the constellation Andromeda lies the constellation Perseus, known for the famous double cluster and Algol, the Demon star.

In early August 1596, astronomer David Fabricius observed a star in constellation Cetus, the sea monster, carefully noting the star’s position and brightness. Eighteen days later he noticed that the star had more than doubled in brightness.