About this world
K2-99 c is a gas giant orbiting K2-99, a yellow, Sun-like star (type G0IV) 1.69 thousand light-years from Earth. It is about 1.1 times the size of Jupiter (its size estimated from its mass), with at least 8.4 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 522 days at 1.4 AU from its star, on a strongly elongated orbit (e = 0.21).
Its equilibrium temperature is about 390 K (117 °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 2022 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. K2-99 has 2 known planets; the others are K2-99 b.