Sirius is the brightest star (in fact, a star system) in the Earth's night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name "Sirius" is derived from the Ancient Greek Σείριος (Seirios), meaning "glowing" or "scorcher". The system has the Bayer designation Alpha Canis Majoris (α CMa). What the naked eye perceives as a single star is actually a binary star system, consisting of a white main-sequence star of spectral type A1V, termed Sirius A, and a faint white dwarf companion of spectral type DA2, called Sirius B. The distance separating Sirius A from its companion varies between 8.2 and 31.5 AU.

Sirius Satellite Radio is a satellite radio (SDARS) service operating in North America, owned by Sirius XM Holdings.