About this world
BD+20 594 b is a sub-Neptune orbiting BD+20 594, a yellow, Sun-like star (type G2V) 585 light-years from Earth. It is about 2.2 times the size of Earth and holds 5.2 Earth masses. It completes an orbit every 41.7 days at 0.22 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 613 K (340 °C): far too hot 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 K2. A planet crosses its star and dims it by a tiny, periodic fraction.