About this world
HD 177830 b is a gas giant orbiting HD 177830, an orange dwarf (type K0) 205 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 1.7 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 410 days at 1.1 AU from its star.
Its equilibrium temperature is about 400 K (126 °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 1999 by radial velocity with W. M. Keck Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. HD 177830 has 2 known planets; the others are HD 177830 c.