About this world
HIP 18606 b is a gas giant orbiting HIP 18606, a giant star (type K0/1III) 153 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 0.77 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 675 days at 1.6 AU from its star.
Its equilibrium temperature is about 406 K (133 °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 2025 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum.