About this world
Kepler-210 b is a sub-Neptune orbiting Kepler-210, a cool red dwarf (type M0V) 759 light-years from Earth. It is about 2.9 times the size of Earth. It completes an orbit every 2.45 days at 0.032 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 737 K (464 °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 2014 by transit with Kepler. A planet crosses its star and dims it by a tiny, periodic fraction. Kepler-210 has 2 known planets; the others are Kepler-210 c.