Who is Alpha Centauri?
Alpha Centauri (α Centauri, α Cen, or Alpha Cen) is a triple star system in the southern constellation of Centaurus. It consists of three stars: Rigil Kentaurus (α Centauri A), Toliman (α Centauri B), and Proxima Centauri (α Centauri C). Proxima Centauri is the closest star to the Sun at 4.2465 light-years (1.3020 pc). α Centauri A and B are Sun-like stars (class G and K, respectively) that together form the binary star system α Centauri AB. To the naked eye, these two main components appear to be a single star with an apparent magnitude of −0.27 . It is the brightest star in the constellation and the third-brightest in the night sky, outshone by only Sirius and Canopus. α Centauri A has 1.1 times the mass and 1.5 times the luminosity of the Sun, while α Centauri B is smaller and cooler, at 0.9 solar mass and less than 0.5 solar luminosity. The pair orbit around a common centre with an orbital period of 79 years. Their elliptical orbit is eccentric, so that the distance betw...
