About this world
GJ 685 b is a sub-Neptune orbiting GJ 685, a cool red dwarf (type M0.5) 46.7 light-years from Earth. It is about 3 times the size of Earth (its size estimated from its mass), with at least 9 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 24.2 days at 0.13 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 369 K (96 °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 Roque de los Muchachos Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum.