Kepler-215 and Its Four Super-Earths

Kepler-215 is a star located 1590 light-years away, and four planets have been identified orbiting it. The star is estimated to be 1.62 billion years old, with a mass of 0.94 solar masses and a radius of 0.85 solar radii. Its temperature is 5680 K. Its reported mass and radius estimates are smaller than the Sun's, and its reported temperature is cooler than the Sun's.

All four planets were discovered by transit in 2014, the method in which a planet passing in front of its star from our viewpoint causes a small dip in observed brightness. Repeated dips help establish orbital periods, the time a planet takes to complete one orbit. Each of the four is classified as a Super-Earth, a size class that reaches 2.5 times Earth's radius.

Kepler-215 b has an orbital period of 9.36 days and a radius of 1.62 Earth radii, the shortest year and smallest radius among the listed planets. Kepler-215 c has an orbital period of 14.7 days and a radius of 1.77 Earth radii, the second-shortest year and second-largest radius. Kepler-215 d has an orbital period of 30.9 days and a radius of 2.39 Earth radii, the second-longest year and largest radius. Kepler-215 e has an orbital period of 68.2 days and a radius of 1.75 Earth radii, the longest year and second-smallest radius. Every one of these radius estimates is larger than Earth's.

The star's reported mass estimate of 0.94 solar masses is smaller than the Sun's.