KOI-55: A Hot B-Type Star With Two Sub-Earth Planets

KOI-55 is a B-type star located 4020 light-years away. Its reported mass estimate is 0.496 solar masses, its reported radius estimate is 0.203 solar radii, and its reported temperature is 27700 K. The star's reported mass and radius estimates are smaller than the Sun's, while its reported temperature is hotter than the Sun's. Two planets are known to orbit this host: KOI-55 b and KOI-55 c. Both were discovered in 2011 by orbital brightness modulation, and both are classified as Sub-Earths.

KOI-55 b has a mass of 0.44 Earth masses and a radius of 0.759 Earth radii. Its reported mass and radius estimates are smaller than Earth's, and its mean density is 5.54 g/cm³, 1.01 times Earth's. It completes an orbit in 0.24 days.

KOI-55 c has a mass of 0.655 Earth masses and a radius of 0.867 Earth radii. Its reported mass and radius estimates are also smaller than Earth's, and its mean density is likewise 5.54 g/cm³, 1.01 times Earth's. Its orbital period is 0.343 days.

Among the listed planets, KOI-55 b has the shortest year by reported estimates, at 0.24 days, and the smallest radius, at 0.759 Earth radii. It also has the smallest reported mass, at 0.44 Earth masses. KOI-55 c has the longest year by reported estimates, at 0.343 days, and the largest radius, at 0.867 Earth radii. It also has the largest reported mass, at 0.655 Earth masses. Both planets circle the same B-type host in less than a day.