About this world
GJ 3293 d is a sub-Neptune orbiting GJ 3293, a cool red dwarf (type M2.5) 65.9 light-years from Earth. It is about 2.7 times the size of Earth (its size estimated from its mass), with at least 7.6 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 48.1 days at 0.19 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 241 K (−32 °C), which places it in the conservative habitable zone: the band where liquid water could exist on a rocky surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2017 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 c.