Kepler-51 e
Kepler-51 e is a super-Earth orbiting Kepler-51 in the constellation Cygnus. It lies about 2,557 light-years from Earth and was discovered in 2024 using the transit timing variations method.
Is Kepler-51 e in the Habitable Zone?
The position of Kepler-51 e relative to the habitable zone of Kepler-51 cannot be precisely determined from the available orbital data.
Habitable zone of Kepler-51: 0.634–1.497 AU (conservative: 0.802–1.419 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Orbit and Year Length
A year on Kepler-51 e — one full orbit around Kepler-51 — lasts 264.3 Earth days, between the years of Mercury (88 days) and Earth (365 days). Its orbit is nearly circular (eccentricity 0.020).
How Was Kepler-51 e Discovered?
Kepler-51 e was discovered in 2024 using the transit timing variations method, with observations from Multiple Observatories.
Transit timing variations reveal a planet through its gravitational tug on a sibling planet, which makes that sibling's transits arrive slightly early or late. The pattern of these deviations betrays the hidden planet's mass and orbit.
How Far Away Is Kepler-51 e?
Kepler-51 e is 2,556.5 light-years (783.8 parsecs) from Earth. Light arriving here tonight left the planet about 2,557 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 44,994,400 years to make the journey.
The Host Star: Kepler-51
Kepler-51
- Surface temperature
- 5,674 K (Sun: 5,772 K)
- Mass
- 0.96 M☉
- Radius
- 0.87 R☉
- Age
- 0.7 billion years (Sun: 4.6)
The Kepler-51 Planetary System
Kepler-51 e is one of 4 known planets in the Kepler-51 system. Its siblings:
- Kepler-51 b (Cold Gas Giant)
- Kepler-51 c (Cold Gas Giant)
- Kepler-51 d (Cold Gas Giant)
Kepler-51 e — Complete Data
| Mass | 5.40 Earth masses (0.017 Jupiter masses) |
|---|---|
| Orbital period | 264.28 days |
| Eccentricity | 0.020 |
| Distance from Earth | 2,556.5 light-years (783.8 parsecs) |
| Constellation | Cygnus |
| Discovery method | Transit Timing Variations |
| Discovery facility | Multiple Observatories |
| Discovery year | 2024 |
Data: NASA Exoplanet Archive, last updated 2024-10-22. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Kepler-51 e
Is Kepler-51 e habitable?
Kepler-51 e is not known to orbit within the habitable zone of Kepler-51, and as a super-Earth it is an unlikely candidate for life as we know it.
How far away is Kepler-51 e?
Kepler-51 e is about 2,557 light-years from Earth in the constellation Cygnus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 44,994,400 years to get there.
How long is a year on Kepler-51 e?
One orbit around Kepler-51 takes 264.3 Earth days.
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