K2-58: A Distant Star With Three Transiting Planets

K2-58 is a star located 593 light-years away. Its reported mass estimate is smaller than the Sun's, at 0.858 solar masses, and its reported radius estimate is also smaller than the Sun's, at 0.803 solar radii. The star's reported temperature is cooler than the Sun's, at 5130 K. Three planets are known to orbit this host: K2-58 b, K2-58 c, and K2-58 d.

All three planets were discovered in 2016 by the transit method, in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness. Repeated dips help establish orbital periods, the time each planet takes to complete one orbit.

K2-58 b is a Neptune-like planet with an orbital period of 7.05 days and a radius of 2.68 Earth radii, larger than Earth's. Among the listed planets, it has the largest radius and the second-shortest year.

K2-58 c is a Super-Earth with an orbital period of 2.54 days and a radius of 1.62 Earth radii, also larger than Earth's. Among the listed planets, it has the shortest year and the smallest radius.

K2-58 d is a Super-Earth with an orbital period of 22.9 days and a radius of 1.71 Earth radii, larger than Earth's as well. Among the listed planets, it has the longest year and the second-smallest radius.