HD 216520 is a star with 0.82 times the mass of the Sun, and 0.76 times its radius. It is located 63.77 light years away from the solar system and is estimated to be 6 billion years old, as compared to the Sun which is roughly 4.6 billion years old.
HD 216520 is known to have 2 exoplanets in orbit around it.
HD 216520 b was discovered by the Multiple Observatories observatory, in 2021-01, using the radial velocity method. Its semi-major axis is 0.20 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of HD 216520 b is 10.265 times the mass of Earth. The radius of HD 216520 b is 3.180 that of Earth. At more than 10 Earth masses, HD 216520 b is an ice giant, a planet that is made up mostly of volatiles like water, amonia and methane, and enveloped by a dense hydrogen and helium atmosphere, much like Uranus and Neptune in our solar system.
HD 216520 c was discovered by the Multiple Observatories observatory, in 2021-01, using the radial velocity method. Its semi-major axis is 0.53 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of HD 216520 c is 9.445 times the mass of Earth. The radius of HD 216520 c is 3.030 that of Earth. At more than 10 Earth masses, HD 216520 c is an ice giant, a planet that is made up mostly of volatiles like water, amonia and methane, and enveloped by a dense hydrogen and helium atmosphere, much like Uranus and Neptune in our solar system.