Kepler-219 and Its Three Planets

Kepler-219 is a star located 2570 light-years away. It is 4.57 billion years old and has a mass of 1.16 solar masses, a radius of 1.43 solar radii, and a temperature of 5910 K. Its reported mass and radius estimates are larger than the Sun's, and its reported temperature is hotter than the Sun's. Three planets are known to orbit this star.

All three planets are Neptune-like and were 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. Kepler-219 b has an orbital period of 4.59 days and a radius of 2.95 Earth radii. Kepler-219 c has an orbital period of 22.7 days and a radius of 3.58 Earth radii. Kepler-219 d has an orbital period of 47.9 days and a radius of 2.81 Earth radii. Each planet's reported radius estimate is larger than Earth's.

Among the listed planets, Kepler-219 b has the shortest year, at 4.59 days, while Kepler-219 c has the second-shortest, at 22.7 days, and Kepler-219 d has the longest, at 47.9 days. In radius, Kepler-219 c is the largest at 3.58 Earth radii, Kepler-219 b is the second-smallest at 2.95 Earth radii, and Kepler-219 d is the smallest at 2.81 Earth radii.