About Kepler-51 d
Kepler-51 d is a rare exoplanet. It lies about 2,556.5 light-years from Earth, shines at apparent magnitude 14.88, has an equilibrium temperature near 381 K and spans roughly 9.7 Earth radii.
Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.