Alpha Centauri
Alpha Centauri is the closest star system and closest planetary system to Earth's Solar System at 4.37 light-years from the Sun. The name is Latinized from α Centauri, and abbreviated Alpha Cen or α Cen. It is a triple star system, consisting of three stars: α Centauri A, α Centauri B, and α Centauri C. Alpha Centauri A and B are Sun-like stars, and together they form the binary star Alpha Centauri AB. To the naked eye, the two main components appear to be a single star with an apparent magnitude of −0.27, the brightest star in the southern constellation of Centaurus and the third-brightest in the night sky, outshone only by Sirius and Canopus. Alpha Centauri A has 1.1 times the mass and 1.519 times the luminosity of the Sun, while Alpha Centauri B is smaller and cooler, at 0.907 times the Sun's mass and 0.445 times its luminosity. The pair orbit around a common centre with an orbital period of 79.91 years.
