The Kepler-204 system contains 2 exoplanets. It is located 2239.79 light years away from the solar system.
| Mass | 1.03 solar masses |
| Radius | 1.24 solar radiae |
| Temperature | 5812 kelvin |
| Stellar Metallicity | 0.01 decimal exponent |
| Age | 3.3 billion years |
At more than 10 Earth masses, Kepler-204 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 | 6.940 Earth masses |
| Density | 2.350 grams per cubic centimeter |
| Radius | 2.530 Earth radiae |
| Semi-major Axis | 0.117 AU |
| Eccentricity | 0 |
| Orbital Period | 14.401 days |
| Discovery Method | Transit |
| Discovery Facility | Kepler |
| Discovery Telescope | 0.95 m Kepler Telescope |
| Discovery Instrument | Kepler CCD Array |
| Discovery Date | 2014-03 |
| Reference | Rowe et al. 2014 |
At 3.848 Earth masses, Kepler-204 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.
| Mass | 3.860 Earth masses |
| Density | 3.700 grams per cubic centimeter |
| Radius | 1.790 Earth radiae |
| Semi-major Axis | 0.173 AU |
| Eccentricity | 0 |
| Orbital Period | 25.661 days |
| Discovery Method | Transit |
| Discovery Facility | Kepler |
| Discovery Telescope | 0.95 m Kepler Telescope |
| Discovery Instrument | Kepler CCD Array |
| Discovery Date | 2014-03 |
| Reference | Rowe et al. 2014 |