K2-9 is a star with 0.3 times the mass of the Sun, and 0.31 times its radius. It is located 270.59 light years away from the solar system and is estimated to be 1 billion years old, as compared to the Sun which is roughly 4.6 billion years old.
K2-9 is known to have 1 exoplanets in orbit around it.
K2-9 b was discovered by the K2 observatory, in 2015-08, using the transit method. Its semi-major axis is 0.09 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of K2-9 b is 5.692 times the mass of Earth. The radius of K2-9 b is 2.250 that of Earth. At more than 10 Earth masses, K2-9 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.