Alpha Centauri A may have a Neptune-sized habitable-zone planet, though it is not yet known to be planetary in nature and could be an artifact of the discovery mechanism. Proxima Centauri has two known planets: Proxima b, an Earth-sized exoplanet in the habitable zone discovered in 2016 and Proxima c, a super-Earth 1.5 AU away, which is possibly surrounded by a huge ring system, discovered in 2019. Currently, the distance between Proxima Centauri and Alpha Centauri AB is about 13,000 AU (0.21 ly), equivalent to about 430 times the radius of Neptune's orbit. Though not visible to the naked eye, Proxima Centauri is the closest star to the Sun at a distance of 4.24 ly (1.30 pc), slightly closer than Alpha Centauri AB. Their elliptical orbit is eccentric, so that the distance between A and B varies from 35.6 AU ( astronomical units), or about the distance between Pluto and the Sun, to 11.2 AU, or about the distance between Saturn and the Sun.Īlpha Centauri C, or Proxima Centauri, is a small and faint red dwarf ( Class M). The pair orbit around a common centre with an orbital period of 79.91 years. 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.Īlpha 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 0.9 times the Sun's mass and 0.445 times its luminosity. Īlpha Centauri A and B are Sun-like stars ( Class G and K, respectively), and together they form the binary star Alpha Centauri AB. It is a triple star system, consisting of the three stars: α Centauri A (officially Rigil Kentaurus), α Centauri B (officially Toliman), and the closest star α Centauri C (officially Proxima Centauri). The name is Latinized from α Centauri, and abbreviated Alpha Cen or α Cen. Α Cen B: Toliman, α 2 Centauri, HR 5460, HD 128621, LHS 51, HIP 71681Īlpha Centauri is a gravitationally bound system of the closest stars and exoplanets to our Solar System at 4.37 light-years (1.34 parsecs) from the Sun. The bright star system to the right is Beta Centauri. Alpha Centauri AB is the bright star to the left, which forms a triple star system with Proxima Centauri, circled in red.
0 kommentar(er)
