The K2-257 system contains 1 exoplanet. It is located 208.76 light years away from the solar system.
| Mass | 0.52 solar masses |
| Radius | 0.5 solar radiae |
| Temperature | 3725 kelvin |
| Stellar Metallicity | -0.03 decimal exponent |
| Age | - billion years |
At less than 1.5 Earth masses, K2-257 b is a terrestrial planet, much like the terrestrial planets we find in our solar system, namely Mercury, Venus, Earth and Mars.
| Mass | 0.498 Earth masses |
| Density | 4.790 grams per cubic centimeter |
| Radius | 0.830 Earth radiae |
| Semi-major Axis | 0.0216 AU |
| Eccentricity | NaN |
| Orbital Period | 1.606 days |
| Discovery Method | Transit |
| Discovery Facility | K2 |
| Discovery Telescope | 0.95 m Kepler Telescope |
| Discovery Instrument | Kepler CCD Array |
| Discovery Date | 2018-08 |
| Reference | Livingston et al. 2018 |