About this world
HD 81817 b is a gas giant orbiting HD 81817, a giant star (type K3III) 878 light-years from Earth. It is about 1.1 times the size of Jupiter (its size estimated from its mass) and holds 24 Jupiter masses. It completes an orbit every 2.8 years at 3.2 AU from its star.
Its equilibrium temperature is about 1,016 K (743 °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 Bohyunsan Optical Astronomical Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. HD 81817 has 2 known planets; the others are HD 81817 c.