Alpha Centauri

Alpha Centauri (α Centauri, α Cen; also known as Rigil Kentaurus, Rigil Kent  /ˈraɪdʒəl/, or Toliman) is the brightest star in the southern constellation of Centaurus. Although it appears to the unaided eye as a single object, Alpha Centauri is actually a binary star system (designated Alpha Centauri AB or α Cen AB) whose combined visual magnitude of -0.27 would qualify it as the third single brightest star in the night sky after -0.72 magnitude Canopus. Its individual component stars are named Alpha Centauri A (α Cen A), with 110% of the mass and 151.9% the luminosity of our Sun, and Alpha Centauri B (α Cen B), at 90.7% of the Sun's mass and 50.0% of its luminosity. During the stars' 79.91 year orbit about a common center, the distance...