About this world
HD 221420 b is a gas giant orbiting HD 221420, a yellow, Sun-like star (type G2IV-V) 102 light-years from Earth. It is about 1.1 times the size of Jupiter (its size estimated from its mass) and holds 23 Jupiter masses. It completes an orbit every 27.6 years at 10 AU from its star.
Its equilibrium temperature is about 123 K (−150 °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 2019 by radial velocity with Anglo-Australian Telescope. The star wobbles toward and away from us, Doppler-shifting its spectrum.