About this world
HD 217107 c is a gas giant orbiting HD 217107, a yellow, Sun-like star (type G) 65.4 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass) and holds 4.4 Jupiter masses. It completes an orbit every 14.1 years at 5.9 AU from its star, on a strongly elongated orbit (e = 0.39).
Its equilibrium temperature is about 123 K (−150 °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 2005 by radial velocity with Lick Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum. HD 217107 has 2 known planets; the others are HD 217107 b.