| Discovery | |
|---|---|
| Discovery site | Kepler Space Observatory |
| Discovery date | 2014 |
| Transit | |
| Orbital characteristics | |
| ~0.136 AU | |
| Eccentricity | null[1] |
| 17.324[1] d | |
| Inclination | null[1] |
| Star | Kepler-277 |
| Physical characteristics | |
| 2.92 +0.73 −0.63[1] R🜨 | |
| Mass | 87.3 +41.7 −39.9[1][2] ME |
Mean density | 19.33+39.9 −13.96 g cm−3 |
| 10.24+14.36 −6.68 g | |
| Temperature | 924 K (651 °C; 1,204 °F)[3] |
Kepler-277b (also known by its Kepler Objects of Interest designation KOI-1215.01) is the second most massive and third-largest rocky planet ever discovered, with a mass close to that of Saturn. Discovered in 2014 by the Kepler Space Telescope, Kepler-277b is a sub-Neptune sized exoplanet with a very high mass and density for an object of its radius, suggesting a composition made mainly of rock and iron. Along with its sister planet, Kepler-277c, the planet's mass was determined using transit-timing variations (TTVs).