Kepler-393 and Its Two Earth-Like Planets

Kepler-393 is a star 2870 light-years away with two planets, both discovered by transit in 2014. A transit occurs when a planet passes in front of its star from our viewpoint, causing a small dip in observed brightness; repeated dips help establish orbital periods. The host star is 2.88 billion years old, holds 1.21 solar masses and 1.34 solar radii, and has a temperature of 6310 K. Its mass and radius estimates are larger than the Sun's, and its temperature is hotter than the Sun's.

The two planets, Kepler-393 b and Kepler-393 c, are both classed as Earth-like, meaning each stays within 1.5 times Earth's radius. Kepler-393 b has an orbital period of 9.18 days and a radius of 1.29 Earth radii, while Kepler-393 c has an orbital period of 14.6 days and a radius of 1.33 Earth radii. Among the listed planets, Kepler-393 b has the shortest year and the smallest radius by reported estimates, and Kepler-393 c has the longest year and the largest radius by reported estimates. Each planet's reported radius estimate is larger than Earth's.