Sirius is a star in the constellation of Canis Major. It is the brightest star in the night sky. Sirius is a binary star system, consisting of a white main-sequence star, Sirius A, and a faint white dwarf companion, Sirius B. The distance between the two stars is about 8.6 light years. The Sirius system is about 25 million years old. The name "Sirius" is derived from the Ancient Greek: ????????, Seirios ("glowing" or "scorcher").