About this world
HD 3651 b is a gas giant orbiting HD 3651, an orange dwarf (type K0V) 36.3 light-years from Earth. It is about 0.9 times the size of Jupiter (its size estimated from its mass), with at least 0.23 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 62.3 days at 0.29 AU from its star, closer than Mercury is to the Sun, on a strongly elongated orbit (e = 0.65).
Its equilibrium temperature is about 433 K (160 °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 2003 by radial velocity with Multiple Observatories. The star wobbles toward and away from us, Doppler-shifting its spectrum.