K2-389: A Sun-Like Star With Two Super-Earths

K2-389 is a star 845 light-years away with two planets orbiting it, both discovered by transit in 2022. The host star has a spectral type of G3, a mass of 0.94 solar masses, a radius of 1.28 solar radii, and a temperature of 5420 K. Its radius is larger than the Sun's, while its temperature is cooler than the Sun's.

Both planets are Super-Earths, a size class that reaches up to 2.5 times Earth's radius. K2-389 b has a radius of 2.33 Earth radii and an orbital period of 8.58 days, giving it the shortest year among the listed planets. K2-389 c has a radius of 2.04 Earth radii and an orbital period of 20.9 days, the longest year among the listed planets. Both planets are larger than Earth. Among the listed planets, K2-389 b has the largest radius at 2.33 Earth radii, and K2-389 c has the smallest at 2.04 Earth radii. 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.