Alpha Centauri B is an orange dwarf star, part of the Alpha Centauri triple star system and among the closest stars to the Sun. In October 2012, astronomers announced that they had found a low-mass planet in orbit around Alpha Centaur B. Its mass is slightly greater than that of the Earth but it orbits so close in - at a distance of 0.04 AU - that its surface temperature is estimated to be around 1200 degrees Celsius. That is comparable to the melting temperatures of many silicate magmas. It is likely that the planet, Alpha Centauri Bb, has a surface which is largely or entirely molten.