Kepler-387: A Distant Star With Two Small Worlds

Kepler-387 is a star located 2610 light-years away, and two planets have been found orbiting it. The host star is 5.5 billion years old and has a mass of 0.95 solar masses, a radius of 1 solar radii, and a temperature of 5890 K. Its reported temperature is hotter than the Sun's.

Both planets were discovered in 2014 using 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-387 b is an Earth-like planet with a radius of 1.03 Earth radii and an orbital period of 6.79 days. Kepler-387 c is a Sub-Earth with a radius of 0.89 Earth radii and an orbital period of 11.8 days. Planet size classes compare radius with Earth's: a Sub-Earth is smaller than Earth, while an Earth-like planet stays within 1.5 times Earth's radius.

Among the listed planets, Kepler-387 b has the shortest year by reported estimates, at 6.79 days, and the largest radius, at 1.03 Earth radii. Kepler-387 c has the longest year by reported estimates, at 11.8 days, and the smallest radius, at 0.89 Earth radii.