Kepler-20e
| Extrasolar planet | List of extrasolar planets | |
|---|---|---|
 | ||
| Parent star | ||
| Star | Kepler-20 (KOI-070) | |
| Constellation | Lyra | |
| Right ascension | (α) | 19h 10m 47.524s |
| Declination | (δ) | +42° 20′ 19.30″ |
| Apparent magnitude | (mV) | 12.51 |
| Mass | (m) | 0.912±0.035 M☉ |
| Radius | (r) | 0.944+0.06 −0.095 R☉ |
| Temperature | (T) | 5466±93 K |
| Metallicity | [Fe/H] | 0.02±0.04 |
| Age | 8.8+4.7 −2.7 Gyr | |
| Physical characteristics | ||
| Mass | (m) | 0.39-1.67 M⊕ |
| Radius | (r) | 0.868+0.074 −0.096 R⊕ |
| Temperature | (T) | 1040 |
| Orbital elements | ||
| Semimajor axis | (a) | 0.0507 AU |
| Eccentricity | (e) | <0.28 |
| Orbital period | (P) | 6.098493 d |
| Inclination | (i) | 87.50+0.33 −0.34}° |
| Discovery information | ||
| Discovery date | 20 December 2011 | |
| Discoverer(s) | Kepler team | |
| Discovery method | Transit (Kepler Mission) | |
| Discovery status | Conference announcement | |
Kepler-20e is an exoplanet orbiting Kepler-20. The planet is notable as it is the first planet with a smaller radius than Earth found orbiting a Sun-like star. The planet is second closest to the star after Kepler-20b, and at 1040 K, it is far too hot to have liquid water on its surface. Along with the other four planets in the system, Kepler-20e was announced on 20 December 2011.
Orbit
Kepler-20e and Kepler-20f compared to Venus and Earth
With a semimajor axis of 0.0507 AUs, Kepler-20e's orbit has a period of 6.098 days (with an extremely small margin of error). The orbit has an inclination of 87.50°, making its transits observable from the Solar System. Like the other planets of the system, the planet has a high maximum eccentricity of 0.28, but the lowest in that system.