About this world
Kepler-54 d is a super-Earth orbiting Kepler-54, a cool red dwarf (type M1V) 886 light-years from Earth. It is about 1.5 times the size of Earth and holds 12 Earth masses. It completes an orbit every 21 days at 0.13 AU from its star, closer than Mercury is to the Sun.
Its equilibrium temperature is about 328 K (55 °C): too cold for liquid water on its surface. By the "cosmic shoreline", it has likely held on to an atmosphere.
It was discovered in 2014 by transit with Kepler. A planet crosses its star and dims it by a tiny, periodic fraction. Kepler-54 has 3 known planets; the others are Kepler-54 b and Kepler-54 c.