K2-158 is a star with 0.92 times the mass of the Sun, and 0.95 times its radius. It is located 643.50 light years away from the solar system.
K2-158 is known to have 2 exoplanets in orbit around it.
K2-158 b was discovered by the K2 observatory, in 2018-03, 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 K2-158 b is 7.473 times the mass of Earth. The radius of K2-158 b is 2.640 that of Earth. At more than 10 Earth masses, K2-158 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.
K2-158 c was discovered by the K2 observatory, in 2018-08, using the transit method. Its semi-major axis is 0.06 astronomical units, as compared to Earth's which is 1 astronomical unit. The mass of K2-158 c is 2.185 times the mass of Earth. The radius of K2-158 c is 1.280 that of Earth. At 2.185 Earth masses, K2-158 c is a so called Super Earth. Super Earths could be terrestrial worlds like Earth, but they could also be ocean worlds or terrestrial worlds wrapped in a substantial atmosphere, in which case some refer to them as Mini Neptunes. No Super Earths are known to exist in our solar system, but if it exists, the so-called Planet Nine could very well be a super Earth, as it is hypothesized to have a mass between five and ten Earth masses.