Kepler-159: A Cool Dwarf and Its Two Transit-Detected Planets

Kepler-159 is an M0 V star, a cool red dwarf, located 1220 light-years away. Its host system contains two planets, both discovered by the transit method in 2014 from dips in the star's observed brightness. The star is 2.51 billion years old, with a mass of 0.76 solar masses and a radius of 0.7 solar radii. Its temperature is 4640 K, and each of these values is below the corresponding solar figure.

Both planets orbit this star, and both are larger than Earth in radius. Kepler-159 b is classified as a Super-Earth, a size class reaching 2.5 times Earth's radius. Its radius is 2.38 Earth radii, and its orbital period is 10.1 days, the shortest year among the listed planets. Kepler-159 c is classified as Neptune-like, a class reaching four times Earth's radius. Its radius is 3.41 Earth radii, and its orbital period is 43.6 days, the longest year among the listed planets. It also has the largest radius among them, while Kepler-159 b has the smallest.