About this world
Kepler-539 b is a Neptune-like planet orbiting Kepler-539, a yellow, Sun-like star (type G2V) 1 thousand light-years from Earth. It is about 0.75 times the size of Jupiter and holds 0.97 Jupiter masses. It completes an orbit every 126 days at 0.5 AU from its star, on a strongly elongated orbit (e = 0.39).
Its equilibrium temperature is about 388 K (114 °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 2016 by transit with Kepler. A planet crosses its star and dims it by a tiny, periodic fraction. Kepler-539 has 2 known planets; the others are Kepler-539 c.