The K2-189 system contains 2 exoplanets. It is located 789.67 light years away from the solar system.
| Mass | 0.94 solar masses |
| Radius | 0.87 solar radiae |
| Temperature | 5519 kelvin |
| Stellar Metallicity | 0 decimal exponent |
| Age | - billion years |
At 2.926 Earth masses, K2-189 b 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.
| Mass | 2.920 Earth masses |
| Density | 4.570 grams per cubic centimeter |
| Radius | 1.520 Earth radiae |
| Semi-major Axis | 0.0361 AU |
| Eccentricity | NaN |
| Orbital Period | 2.588 days |
| Discovery Method | Transit |
| Discovery Facility | K2 |
| Discovery Telescope | 0.95 m Kepler Telescope |
| Discovery Instrument | Kepler CCD Array |
| Discovery Date | 2018-03 |
| Reference | Mayo et al. 2018 |
At more than 10 Earth masses, K2-189 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.
| Mass | 6.800 Earth masses |
| Density | 2.390 grams per cubic centimeter |
| Radius | 2.500 Earth radiae |
| Semi-major Axis | 0.068 AU |
| Eccentricity | NaN |
| Orbital Period | 6.679 days |
| Discovery Method | Transit |
| Discovery Facility | K2 |
| Discovery Telescope | 0.95 m Kepler Telescope |
| Discovery Instrument | Kepler CCD Array |
| Discovery Date | 2018-03 |
| Reference | Mayo et al. 2018 |