About this world
K2-24 b is a Neptune-like planet orbiting K2-24, a yellow, Sun-like star (type G9V) 556 light-years from Earth. It is about 5.6 times the size of Earth and holds 21 Earth masses. It completes an orbit every 20.9 days at 0.17 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 732 K (459 °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 2016 by transit with K2. A planet crosses its star and dims it by a tiny, periodic fraction. K2-24 has 2 known planets; the others are K2-24 c.