Kepler-431 and Its Three Small Worlds

Kepler-431 is a star located 1590 light-years away, and three planets have been found orbiting it. The host star is estimated to be 4.27 billion years old, with a mass of 1.15 solar masses, a radius of 1.41 solar radii, and a temperature of 6090 K. Its reported mass and radius estimates are larger than the Sun's, and its reported temperature is hotter than the Sun's.

All three planets were discovered by transit in 2015, the method in which a planet passes in front of its star from our viewpoint and causes a small dip in observed brightness. Kepler-431 b is a Sub-Earth with a radius of 0.764 Earth radii, smaller than Earth's, and an orbital period of 6.8 days, the shortest year among the listed planets. Kepler-431 c is also a Sub-Earth, with a radius of 0.668 Earth radii, smaller than Earth's and the smallest among the listed planets, and an orbital period of 8.7 days, the second-shortest year among them. Kepler-431 d is Earth-like, with a radius of 1.11 Earth radii, larger than Earth's and the largest among the listed planets, and an orbital period of 11.9 days, the longest year among them.