Kepler-282 and Its Four Planets

Kepler-282 is a star 4360 light-years away with four planets. The host star is 5.25 billion years old and has a mass of 0.9 solar masses and a radius of 0.89 solar radii, both smaller than the Sun's. Its temperature of 5700 K is cooler than the Sun's. All four planets were found 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, which are stated in days.

Kepler-282 b and Kepler-282 c are Earth-like planets, a size class that stays within 1.5 times Earth's radius. Kepler-282 b has a radius of 1.01 Earth radii and an orbital period of 9.22 days, the shortest year among the listed planets. Kepler-282 c has a radius of 1.2 Earth radii, the second-smallest among the listed planets, and an orbital period of 13.6 days, the second-shortest.

Kepler-282 d is a Super-Earth, a size class reaching 2.5 times Earth's radius. It has a radius of 2.46 Earth radii, larger than Earth's and the second-largest among the listed planets, and a mass of 61 Earth masses, larger than Earth's. Its orbital period is 24.8 days, the second-longest among the listed planets. Its mean density is 22.6 g/cm³, 4.1 times Earth's.

Kepler-282 e is a Neptune-like planet, a size class reaching 4 times Earth's radius. It has the largest radius among the listed planets at 3.1 Earth radii, larger than Earth's, and a mass of 56.2 Earth masses, also larger than Earth's. Its mean density is 10.4 g/cm³, 1.89 times Earth's. Its orbital period of 44.3 days is the longest year among the listed planets.