The planet is estimated to be about five times Earth's mass (5.5+5.5?2.7 M?). Some astronomers have speculated that it may have a rocky core like Earth, with a thin atmosphere. Its distance from the star, and the star's relatively low temperature, means that the planet's likely surface temperature is around 53 K (?220 °C, ?364 °F). If it is a rocky world, this temperature would make it likely that the surface would be made of frozen volatiles, substances which would be liquids or gases on Earth: water, ammonia, methane and nitrogen would all be frozen solid. If it is not a rocky planet, it would more closely resemble an icy gas planet like Uranus, although much smaller. [2]