About this world
HD 13931 b is a gas giant orbiting HD 13931, a yellow, Sun-like star (type G0) 155 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass) and holds 2.8 Jupiter masses. It completes an orbit every 11.5 years at 5.2 AU from its star.
Its equilibrium temperature is about 139 K (−134 °C): too cold for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2009 by radial velocity with W. M. Keck Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum.