Kepler-238 and Its Five Planets

Kepler-238 is a star located 5,870 light-years away, and it hosts five planets. The star is 6.76 billion years old, with a mass of 1.06 solar masses, a radius of 1.26 solar radii, and a temperature of 5730 K. Its reported mass estimate is larger than the Sun's, and its reported radius estimate is also larger than the Sun's.

The five planets around Kepler-238 were all found by the transit method, which detects a planet when it passes in front of its star from our viewpoint and causes a small dip in observed brightness. Kepler-238 b, c, and f are classified as Super-Earths, Kepler-238 d is Neptune-like, and Kepler-238 e is Jupiter-like. These size classes compare planetary radius with Earth's rather than indicating composition. Kepler-238 b, c, d, e, and f all have reported radius estimates larger than Earth's, and Kepler-238 e and f have reported mass estimates larger than Earth's.

Kepler-238 b has a radius of 1.73 Earth radii and an orbital period of 2.09 days. Kepler-238 c has a radius of 2.39 Earth radii and an orbital period of 6.16 days. Kepler-238 d has a radius of 3.07 Earth radii and an orbital period of 13.2 days. Kepler-238 e has a mass of 170 Earth masses, a radius of 5.6 Earth radii, an orbital period of 23.7 days, and a mean density of 5.32 g/cm³, 0.966 times Earth's. Kepler-238 f has a mass of 13.5 Earth masses, a radius of 2 Earth radii, an orbital period of 50.4 days, and a mean density of 9.3 g/cm³, 1.69 times Earth's. Among the listed planets, Kepler-238 b has the shortest year by reported estimates, at 2.09 days, and the smallest radius, at 1.73 Earth radii. Kepler-238 f has the longest year by reported estimates, at 50.4 days. Kepler-238 e has the largest radius by reported estimates, at 5.6 Earth radii.