About this world
K2-105 c is a sub-Neptune orbiting K2-105, a yellow, Sun-like star (type G9V) 646 light-years from Earth. It is about 3.3 times the size of Earth (its size estimated from its mass), with at least 11 Earth masses (a minimum, measured by radial velocity). It completes an orbit every 5.02 days at 0.056 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 1,037 K (764 °C): far too hot for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium.
It was discovered in 2026 by radial velocity with Paranal Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. K2-105 has 2 known planets; the others are K2-105 b.