About this world
K2-312 c is a gas giant orbiting HD 80653, a yellow, Sun-like star (type G0V) 358 light-years from Earth. It is about 1.1 times the size of Jupiter (its size estimated from its mass), with at least 5.3 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 2.39 years at 1.9 AU from its star, on a strongly elongated orbit (e = 0.84).
Its equilibrium temperature is about 229 K (−44 °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 2023 by radial velocity with Roque de los Muchachos Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. HD 80653 has 2 known planets; the others are HD 80653 b.