Kepler-27: A Distant Star With Three Known Planets

Kepler-27 is a star located 3410 light-years away. It is host to three planets. The star's reported mass estimate is 0.95 solar masses, its radius estimate is 0.85 solar radii, and its temperature is 5290 K; each of these estimates is smaller or cooler than the corresponding value for the Sun. Its age is 1.62 billion years.

All three planets were found by the transit method. A transit occurs when a planet passes in front of its star from our viewpoint, causing a small dip in observed brightness.

Kepler-27 b and Kepler-27 c are both Jupiter-like planets, a size class that exceeds 4 times Earth's radius. Kepler-27 b has a radius of 4 Earth radii and a reported upper limit of 2895.31 Earth masses, with an orbital period of 15.3 days. Kepler-27 c is the largest of the listed planets by reported estimates, at 4.9 Earth radii, and carries a reported upper limit of 4385.87 Earth masses; its orbital period of 31.3 days is the longest among the listed planets. Both were discovered in 2011.

Kepler-27 d is a Neptune-like planet, a class reaching up to 4 times Earth's radius. Its radius is 2.71 Earth radii, the smallest among the listed planets by reported estimates, and its orbital period of 6.55 days is the shortest among them. It was discovered in 2021.

Each of the three planets has a reported radius estimate larger than Earth's, and together they complete the set of worlds known to orbit this star.