About this world
GJ 163 d is a Neptune-like planet orbiting GJ 163, a cool red dwarf (type M) 49.3 light-years from Earth. It is about 5.9 times the size of Earth (its size estimated from its mass), with at least 29 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 604 days at 1 AU from its star, on a strongly elongated orbit (e = 0.37).
Its equilibrium temperature is about 106 K (−167 °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 2013 by radial velocity with La Silla Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. GJ 163 has 3 known planets; the others are GJ 163 b and GJ 163 c.