Kepler-549 and Its Three Known Planets

Kepler-549 is a star located 2070 light-years away, and it hosts three known planets. The star is estimated to be 4.57 billion years old, with a mass of 0.88 solar masses, a radius of 0.84 solar radii, and a temperature of 5360 K. Its reported mass and radius estimates are both smaller than the Sun's, and its reported temperature is cooler than the Sun's.

All three planets were found by the transit method, in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness. Kepler-549 b and Kepler-549 c were discovered in 2016, while Kepler-549 d was discovered in 2023.

Kepler-549 b is a Neptune-like planet with an orbital period of 42.9 days and a radius of 2.57 Earth radii. Kepler-549 c is also Neptune-like, with an orbital period of 117 days and a radius of 2.93 Earth radii. Kepler-549 d is a Jupiter-like planet with an orbital period of 24.6 days and a radius of 4.2 Earth radii. Each planet's reported radius estimate is larger than Earth's.

Among the listed planets, Kepler-549 d has the shortest year, at 24.6 days, and the largest radius, at 4.2 Earth radii. Kepler-549 c has the longest year, at 117 days, and the second-smallest radius, at 2.93 Earth radii. Kepler-549 b has the second-shortest year, at 42.9 days, and the smallest radius, at 2.57 Earth radii.