The Kepler-51 system contains 3 exoplanets. It is located 2556.51 light years away from the solar system.
| Mass | 1.04 solar masses |
| Radius | 0.94 solar radiae |
| Temperature | 6018 kelvin |
| Stellar Metallicity | 0.05 decimal exponent |
| Age | 0.3 billion years |
With a mass below 5 Earth masses, a density of 0.03, and a semi-major axis of 0.2514 astronomical units, Kepler-51 b could, potentially, be an ocean world - a planet with no dry land.
| Mass | 2.100 Earth masses |
| Density | 0.030 grams per cubic centimeter |
| Radius | 7.100 Earth radiae |
| Semi-major Axis | 0.2514 AU |
| Eccentricity | 0.04 |
| Orbital Period | 45.154 days |
| Discovery Method | Transit |
| Discovery Facility | Kepler |
| Discovery Telescope | 0.95 m Kepler Telescope |
| Discovery Instrument | Kepler CCD Array |
| Discovery Date | 2013-01 |
| Reference | Steffen et al. 2013 |
With a mass below 5 Earth masses, a density of 0.03, and a semi-major axis of 0.384 astronomical units, Kepler-51 c could, potentially, be an ocean world - a planet with no dry land.
| Mass | 4.000 Earth masses |
| Density | 0.030 grams per cubic centimeter |
| Radius | 9.000 Earth radiae |
| Semi-major Axis | 0.384 AU |
| Eccentricity | 0.014 |
| Orbital Period | 85.312 days |
| Discovery Method | Transit |
| Discovery Facility | Kepler |
| Discovery Telescope | 0.95 m Kepler Telescope |
| Discovery Instrument | Kepler CCD Array |
| Discovery Date | 2013-01 |
| Reference | Steffen et al. 2013 |
At more than 10 Earth masses, Kepler-51 d 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 | 7.600 Earth masses |
| Density | 0.046 grams per cubic centimeter |
| Radius | 9.700 Earth radiae |
| Semi-major Axis | 0.509 AU |
| Eccentricity | 0.008 |
| Orbital Period | 130.194 days |
| Discovery Method | Transit |
| Discovery Facility | Kepler |
| Discovery Telescope | 0.95 m Kepler Telescope |
| Discovery Instrument | Kepler CCD Array |
| Discovery Date | 2014-03 |
| Reference | Masuda 2014 |