Because a red giant is so large ... Sirius, or the Dog Star, greatly outshines its white dwarf companion, Sirius B. At 8.6 light-years away, Sirius B is the nearest known white dwarf star to ...

Astronomers measure a star’s brightness using the apparent magnitude system, where lower values indicate brighter stars.

This week’s first small-telescope target is Sirius B, the companion to the night sky’s brightest star, Alpha (α) Canis Majoris. American telescope-maker Alvin Graham Clark discovered that ...