Kepler-1311 and Its Three Planets

Kepler-1311 is a star located 2830 light-years away, and three planets have been found orbiting it. The host star is 7.59 billion years old, with a mass of 1.05 solar masses, a radius of 1.4 solar radii, and a temperature of 5750 K. Its reported radius estimate is larger than the Sun's.

All three planets were detected 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; repeated dips help establish orbital periods.

Kepler-1311 b and Kepler-1311 c are both Earth-like in size class, meaning their radii stay within 1.5 times Earth's radius. Kepler-1311 b has an orbital period of 11.2 days and a radius of 1.24 Earth radii. Kepler-1311 c has an orbital period of 2.54 days and a radius of 1.22 Earth radii. Among the listed planets, Kepler-1311 c has the shortest year and the smallest radius, while Kepler-1311 b has the second-shortest year and the second-smallest radius.

Kepler-1311 d is Jupiter-like, a class for planets exceeding 4 times Earth's radius. It has an orbital period of 198 days and a radius of 9.66 Earth radii, larger than Earth's. Among the listed planets, it has the longest year and the largest radius.