Kepler-1181 and Its Two Super-Earths

Kepler-1181 is a star located 3060 light-years away, and two planets have been found orbiting it. The host star is estimated to be 3.24 billion years old, with a mass of 1.17 solar masses and a radius of 1.3 solar radii. Its reported temperature is 6180 K, hotter than the Sun's, and both its mass and radius are larger than the Sun's.

Both known planets are classified as Super-Earths, a size class that reaches up to 2.5 times Earth's radius. Kepler-1181 b was discovered by transit in 2016. It completes an orbit in 4.89 days, among the listed planets the shortest year, and has a radius of 1.57 Earth radii, the smallest radius among the listed planets. Kepler-1181 c was discovered by transit in 2023. It orbits in 8.93 days, the longest year among the listed planets, and has a radius of 1.83 Earth radii, the largest radius among the listed planets. Both planets' reported radius estimates are larger than Earth's. A transit occurs when a planet passes in front of its star from our viewpoint, causing a small dip in observed brightness, and repeated dips help establish orbital periods.