Kepler-58 and Its Four Planets

Kepler-58 is a star located 3160 light-years away, and four planets have been reported orbiting it. The star is estimated to be 2.14 billion years old, with a mass of 1.33 solar masses, a radius of 1.5 solar radii, and a temperature of 6430 K. Its mass, radius, and temperature estimates are each larger or hotter than the Sun's corresponding values.

All four planets were found by the transit method, in which a planet passing in front of its star from our viewpoint causes a small dip in observed brightness; repeated dips help establish orbital periods. Kepler-58 b and Kepler-58 c were reported in 2012, Kepler-58 d in 2014, and Kepler-58 e in 2023. The first three are Neptune-like, a size class reaching four times Earth's radius, while Kepler-58 e is a Super-Earth, reaching 2.5 times Earth's radius. Every listed planet's radius estimate is larger than Earth's.

Kepler-58 e has the shortest year among the listed planets, at 4.46 days, and the smallest radius, at 1.61 Earth radii. Kepler-58 b has the second-shortest year, at 10.2 days, and the second-smallest radius, at 2.78 Earth radii; its reported upper mass limit is 35.5 Earth masses. Kepler-58 c has the second-longest year, at 15.6 days, and the second-largest radius, at 2.86 Earth radii; its reported upper mass limit is 53 Earth masses. Kepler-58 d has the longest year, at 40.1 days, and the largest radius, at 2.94 Earth radii.