Sirius is the brightest star in the night sky with a visual apparent magnitude of −1.47, almost twice as bright as Canopus, the next brightest star. Pronounced /ˈsɪriəs/, the name Sirius is derived from the Ancient Greek Σείριος. The star has the Bayer designation α Canis Majoris (α CMa, or Alpha Canis Majoris). 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, termed Sirius B.