About this world
K2-111 c is a sub-Neptune orbiting K2-111, a yellow, Sun-like star (type G2) 654 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 15.7 days at 0.12 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 923 K (650 °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 2020 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. K2-111 has 2 known planets; the others are K2-111 b.