About this world
K2-146 c is a sub-Neptune orbiting K2-146, a cool red dwarf (type M3.0V) 259 light-years from Earth. It is about 2.2 times the size of Earth and holds 7.5 Earth masses. It completes an orbit every 4 days at 0.033 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 519 K (245 °C): far too hot for liquid water on its surface. By the "cosmic shoreline", it has likely held on to an atmosphere.
It was discovered in 2019 by transit with K2. A planet crosses its star and dims it by a tiny, periodic fraction. K2-146 has 2 known planets; the others are K2-146 b.