Kepler-126: A Distant Star With Three Known Worlds

Kepler-126 is a star located 774 light-years away, and three planets have been identified in orbit around it. The star is estimated to be 3.39 billion years old, with a mass of 1.18 solar masses and a radius of 1.35 solar radii. Its temperature is 6310 K. Compared with the Sun, the star's reported mass and radius estimates are larger, and its reported temperature is hotter.

All three planets were discovered 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; repeated dips help establish orbital periods. Each planet completes one orbit, its year, in a period measured in days.

Kepler-126 b is classified as a Super-Earth. It has an orbital period of 10.5 days and a radius of 1.52 Earth radii. Kepler-126 c is also a Super-Earth, with an orbital period of 21.9 days and a radius of 1.58 Earth radii. Kepler-126 d is Neptune-like, with an orbital period of 100 days and a radius of 2.5 Earth radii. All three planets have reported radius estimates larger than Earth's.

Among the listed planets, Kepler-126 b has the shortest year by reported estimates, at 10.5 days, and the smallest radius, at 1.52 Earth radii. Kepler-126 c has the second-shortest year, at 21.9 days, and the second-smallest radius, at 1.58 Earth radii. Kepler-126 d has the longest year, at 100 days, and the largest radius, at 2.5 Earth radii.