About this world
HD 221585 b is a gas giant orbiting HD 221585, a yellow, Sun-like star (type G8IV) 182 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 1.6 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 3.21 years at 2.3 AU from its star.
Its equilibrium temperature is about 243 K (−30 °C), which places it in the conservative habitable zone: the band where liquid water could exist on a rocky surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2016 by radial velocity with Haute-Provence Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum.