About this world
HD 205739 b is a gas giant orbiting HD 205739, a yellow-white F-type star (type F7V) 302 light-years from Earth. It is about 1.2 times the size of Jupiter (its size estimated from its mass), with at least 1.4 Jupiter masses (a minimum, measured by radial velocity). It completes an orbit every 280 days at 0.9 AU from its star, on a strongly elongated orbit (e = 0.27).
Its equilibrium temperature is about 363 K (90 °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 2008 by radial velocity with Las Campanas Observatory. The star wobbles toward and away from us, Doppler-shifting its spectrum.