About this world
GJ 504 b is a gas giant orbiting GJ 504, a yellow, Sun-like star (type G0V) 57.2 light-years from Earth. It is about 1.1 times the size of Jupiter and holds 4 Jupiter masses.
Its equilibrium temperature is about 510 K (237 °C): far too hot for liquid water on its surface. At its size it almost certainly keeps a deep envelope of hydrogen and helium. Its atmosphere has already been studied in one spectroscopic observation.
It was discovered in 2013 by direct imaging with Subaru Telescope. The planet itself is photographed, its star blocked by a coronagraph.