About this world
Kepler-439 b is a sub-Neptune orbiting Kepler-439, a yellow, Sun-like star 2.47 thousand light-years from Earth. It is about 2.2 times the size of Earth. It completes an orbit every 178 days at 0.56 AU from its star.
Its equilibrium temperature is about 291 K (18 °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 2015 by transit with Kepler. A planet crosses its star and dims it by a tiny, periodic fraction.