About this world
HIP 111909 c is a gas giant orbiting HIP 111909, a giant star (type K1III) 287 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 0.81 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 2.45 years at 2 AU from its star.
Its equilibrium temperature is about 358 K (84 °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 2025 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum. HIP 111909 has 2 known planets; the others are HIP 111909 b.