HD 216520 and Its Two Known Planets

HD 216520 is a K2 star located 63.8 light-years from Earth. It has a reported age of 6 billion years, a mass of 0.82 solar masses, a radius of 0.76 solar radii, and a temperature of 5100 K. The star's reported mass and radius are smaller than the Sun's, and its temperature is cooler than the Sun's. Two planets are known to orbit this host.

HD 216520 b was discovered in 2020 by the radial velocity method, which measures the wobble a planet's gravity induces in its star's motion. Its minimum mass is 10.3 Earth masses, larger than Earth's, and its orbital period is 35.5 days, the shortest among the listed planets. HD 216520 c, also found in 2020 by radial velocity, has a minimum mass of 9.44 Earth masses, larger than Earth's, and an orbital period of 154 days, the longest among the listed planets. Among the listed planets, HD 216520 b has the largest minimum mass and HD 216520 c has the smallest.