The K2-18 system contains 2 exoplanets. It is located 124.03 light years away from the solar system.
| Mass | 0.36 solar masses |
| Radius | 0.41 solar radiae |
| Temperature | 3457 kelvin |
| Stellar Metallicity | 0.12 decimal exponent |
| Age | - billion years |
At more than 10 Earth masses, K2-18 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.
| Mass | 8.920 Earth masses |
| Density | 4.110 grams per cubic centimeter |
| Radius | 2.370 Earth radiae |
| Semi-major Axis | 0.1429 AU |
| Eccentricity | 0.2 |
| Orbital Period | 32.940 days |
| Discovery Method | Transit |
| Discovery Facility | K2 |
| Discovery Telescope | 0.95 m Kepler Telescope |
| Discovery Instrument | Kepler CCD Array |
| Discovery Date | 2015-08 |
| Reference | Montet et al. 2015 |
At more than 10 Earth masses, K2-18 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 | 7.510 Earth masses |
| Density | 2.220 grams per cubic centimeter |
| Radius | 2.650 Earth radiae |
| Semi-major Axis | 0.06 AU |
| Eccentricity | 0.47 |
| Orbital Period | 8.962 days |
| Discovery Method | Radial Velocity |
| Discovery Facility | La Silla Observatory |
| Discovery Telescope | 3.6 m ESO Telescope |
| Discovery Instrument | HARPS Spectrograph |
| Discovery Date | 2017-12 |
| Reference | Cloutier et al. 2017 |