Kepler-125: A Small Red Dwarf and Its Two Worlds

Kepler-125 is a star located 598 light-years away, and two planets have been found in orbit around it. The star is an M1 V dwarf, a small, cool red dwarf with a reported mass of 0.53 solar masses and a radius of 0.51 solar radii, both smaller than the Sun's. Its temperature of 3820 K is cooler than the Sun's, and its age is placed at 3.8 billion years.

Both planets were discovered by the transit method in 2014, in which a planet passing in front of its star dims the starlight from our viewpoint. Kepler-125 b is a Super-Earth with a radius of 2.37 Earth radii, larger than Earth's, and it completes an orbit in 4.16 days. Kepler-125 c is a Sub-Earth with a radius of 0.74 Earth radii, smaller than Earth's, and its orbital period is 5.77 days. Among the listed planets, Kepler-125 b has the shortest year and the largest radius, while Kepler-125 c has the longest year and the smallest radius.