Kepler-189 and Its Two Known Planets

Kepler-189 is a star located 1930 light-years away. It is 5.13 billion years old, with a mass of 0.83 solar masses and a radius of 0.8 solar radii. Its temperature is 5170 K. The star's reported mass and radius estimates are smaller than the Sun's, and its reported temperature is cooler than the Sun's. Two planets are known to orbit this host.

Kepler-189 b and Kepler-189 c were 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. Kepler-189 b is classified as Earth-like, with a radius of 1.21 Earth radii and an orbital period of 10.4 days. Kepler-189 c is classified as a Super-Earth, with a radius of 2.38 Earth radii and an orbital period of 20.1 days. Kepler-189 c's reported radius estimate is larger than Earth's.

Among the listed planets, Kepler-189 b has the shortest year by reported estimates, at 10.4 days, and the smallest radius, at 1.21 Earth radii. Kepler-189 c has the longest year, at 20.1 days, and the largest radius, at 2.38 Earth radii.