About this world
HD 109988 b is a gas giant orbiting HD 109988, an orange dwarf 139 light-years from Earth. It is about 1.1 times the size of Jupiter (its size estimated from its mass) and holds 22 Jupiter masses. It completes an orbit every 46.9 years at 13 AU from its star.
Its equilibrium temperature is about 66 K (−207 °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.