Kepler-487: A Distant Star With Three Known Planets

Kepler-487 is a star located 2850 light-years away, and it hosts three known planets. The star is estimated to be 5.62 billion years old, with a reported mass of 0.91 solar masses and a reported radius of 0.88 solar radii. Its reported temperature is 5440 K. The star's reported mass estimate is smaller than the Sun's, its reported radius estimate is 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-487 b was discovered in 2016. It is Jupiter-like, with a reported radius of 11.4 Earth radii and an orbital period of 15.4 days. Kepler-487 c was also discovered in 2016. It is Neptune-like, with a reported radius of 2.68 Earth radii and an orbital period of 38.7 days. Kepler-487 d was discovered in 2021. It is also Neptune-like, with a reported radius of 2.78 Earth radii and an orbital period of 2.42 days.

Among the listed planets, Kepler-487 b has the largest radius by reported estimates, at 11.4 Earth radii, and its reported radius estimate is larger than Earth's. Kepler-487 c has the smallest radius by reported estimates, at 2.68 Earth radii, and Kepler-487 d has the second-smallest radius by reported estimates, at 2.78 Earth radii; both of their reported radius estimates are larger than Earth's. In orbital period, Kepler-487 d has the shortest year by reported estimates, at 2.42 days, while Kepler-487 b has the second-shortest year by reported estimates, at 15.4 days, and Kepler-487 c has the longest year by reported estimates, at 38.7 days.