Kepler-111: A Star and Its Two Known Planets

Kepler-111 is a star located 2,140 light-years away with two planets discovered in 2014, both by the transit method. A transit occurs when a planet passes in front of its star from our viewpoint, causing a small dip in observed brightness; repeated dips help establish orbital periods. The host star is 3.4 billion years old and has a mass of 1.12 solar masses, a radius of 1.15 solar radii, and a temperature of 5910 K. Its reported mass and radius estimates are larger than the Sun’s, and its reported temperature is hotter than the Sun’s.

Kepler-111 b is a Super-Earth, a size class that reaches 2.5 times Earth's radius. It has a radius of 1.58 Earth radii, larger than Earth’s, and an orbital period of 3.34 days. Among the listed planets, it has the shortest year and the smallest radius by reported estimates.

Kepler-111 c is a Jupiter-like planet, a class that exceeds 4 times Earth's radius. Its radius is 7.08 Earth radii, larger than Earth’s, and its mass is 222 Earth masses, larger than Earth’s. Its orbital period is 225 days. Among the listed planets, it has the longest year and the largest radius by reported estimates. Kepler-111 c’s mean density is 3.45 g/cm³, 0.626 times Earth's.