About this world
GJ 3512 b is a gas giant orbiting GJ 3512, a cool red dwarf (type M5.5V) 30.9 light-years from Earth. It is about 1.3 times the size of Jupiter (its size estimated from its mass), with at least 0.46 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 203 days at 0.34 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.43).
Its equilibrium temperature is about 97 K (−176 °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 Calar Alto Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. GJ 3512 has 2 known planets; the others are GJ 3512 c.