About this world
GJ 3293 c is a Neptune-like planet orbiting GJ 3293, a cool red dwarf (type M2.5) 65.9 light-years from Earth. It is about 4.9 times the size of Earth (its size estimated from its mass), with at least 21 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 123 days at 0.36 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 177 K (−97 °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 2015 by radial velocity with La Silla Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. GJ 3293 has 4 known planets; the others are GJ 3293 e, GJ 3293 b and GJ 3293 d.