About this world
HD 2039 b is a gas giant orbiting HD 2039, a yellow, Sun-like star (type G2/G3IV) 279 light-years from Earth. It is about 1.1 times the size of Jupiter (its size estimated from its mass), with at least 6.3 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 3.07 years at 2.2 AU from its star, on a strongly elongated orbit (e = 0.71).
Its equilibrium temperature is about 211 K (−62 °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 2002 by radial velocity with Anglo-Australian Telescope. The star wobbles toward and away from us, Doppler-shifting its spectrum.