About this world
GJ 3021 b is a gas giant orbiting GJ 3021, a yellow, Sun-like star (type G6V) 57.3 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 3.4 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 134 days at 0.49 AU from its star, on a strongly elongated orbit (e = 0.51).
Its equilibrium temperature is about 350 K (77 °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 2000 by radial velocity with La Silla Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum.