Kepler-80 and Its Six-Planet System

Kepler-80 is a K5 star located 1200 light-years away. Its reported mass estimate is 0.73 solar masses, smaller than the Sun's, and its reported radius estimate is 0.678 solar radii, also smaller than the Sun's. The star's reported temperature of 4540 K is cooler than the Sun's, and its age is 2 billion years. Six planets are known to orbit this host.

The two Neptune-like planets, Kepler-80 b and Kepler-80 c, are the largest of the set. Kepler-80 b has a radius of 2.67 Earth radii, larger than Earth's, and a mass of 6.93 Earth masses, also larger than Earth's, with a mean density of 2.01 g/cm³, 0.364 times Earth's; its orbital period is 7.05 days. Kepler-80 c has a radius of 2.74 Earth radii, larger than Earth's, and a mass of 6.74 Earth masses, also larger than Earth's, with a mean density of 1.81 g/cm³, 0.328 times Earth's; its orbital period is 9.52 days. Among the listed planets, Kepler-80 c has the largest radius, and Kepler-80 b has the second-largest radius.

The Super-Earths Kepler-80 d and Kepler-80 e are smaller. Kepler-80 d has a radius of 1.53 Earth radii, larger than Earth's, and a mass of 6.75 Earth masses, larger than Earth's, with a mean density of 10.4 g/cm³, 1.88 times Earth's; its orbital period of 3.07 days is the second-shortest among the listed planets. Kepler-80 e has a radius of 1.6 Earth radii, larger than Earth's, and a mass of 4.13 Earth masses, larger than Earth's, with a mean density of 5.56 g/cm³, 1.01 times Earth's; its orbital period is 4.64 days.

The Earth-like planets are the smallest. Kepler-80 f has a radius of 1.21 Earth radii, larger than Earth's, and an orbital period of 0.987 days, the shortest among the listed planets; it has the second-smallest radius of the set. Kepler-80 g has a radius of 1.13 Earth radii, the smallest among the listed planets, and an orbital period of 14.6 days, the longest among the listed planets.