Exoplanets in the Alpha Centauri System
There are three stars in the Alpha Centauri system: Alpha Centauri A, Alpha Centauri B, and Proxima Centauri. This is the closest star system to Earth at only 4.3 light years away. Alpha Centauri A and B are similar to our Sun, while Proxima Centauri is smaller and redder.
An Earth-sized exoplanet was discovered in 2012 orbiting Alpha Centauri B. It was found by examining the tiny changes in the star’s motion caused by the slight gravitational pull of the planet. The planet orbits about 6 million kilometers from the star, closer than Mercury and our Sun. This is the first planet of a mass similar to the Earth found orbiting a Sun-like star. Most exoplanets are large, closer to Jupiter’s size. While this exoplanet is much to close and hot for life, there may be other planets in the system not yet detected.
Image and information from ESO.