About Kepler-257 b
Kepler-257 b is a rare exoplanet. It lies about 2,544.9 light-years from Earth, shines at apparent magnitude 15.65, has an equilibrium temperature near 1,237 K and spans roughly 2.61 Earth radii.
It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.