Kepler-123 and Its Two Known Worlds

Kepler-123 is a single star located 3330 light-years away. Its reported mass estimate is 1.12 solar masses, its radius estimate is 1.21 solar radii, and its temperature is 6150 K, all larger or hotter than the Sun's corresponding values. The star is 3.55 billion years old. Two planets are known to orbit it, both discovered in 2014 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.

The two planets differ in size and year. Kepler-123 b is Neptune-like, with a radius estimate of 2.94 Earth radii and an orbital period of 17.2 days. Kepler-123 c is Earth-like, with a radius estimate of 1.48 Earth radii and an orbital period of 26.7 days. Both radii are larger than Earth's. Among the listed planets, Kepler-123 b has the shortest year and the largest radius, while Kepler-123 c has the longest year and the smallest radius.