About this world
GJ 687 c is a Neptune-like planet orbiting GJ 687, a cool red dwarf (type M3.0V) 14.8 light-years from Earth. It is about 4.1 times the size of Earth (its size estimated from its mass), with at least 16 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 728 days at 1.2 AU from its star, on a strongly elongated orbit (e = 0.4).
Its equilibrium temperature is about 99 K (−175 °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 2020 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. GJ 687 has 2 known planets; the others are GJ 687 b.