The Kepler-51 System
Kepler-51 is a planetary system in the constellation Cygnus hosting 4 confirmed exoplanets, about 2,557 light-years from Earth.
Size Comparison: The Planets of Kepler-51
Planets without a measured radius are not shown.
Kepler-51: Star and Habitable Zone
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)
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 ›
All 4 Planets in the Kepler-51 System
| Planet | Type | Orbit | Radius | ESI | Discovered |
|---|---|---|---|---|---|
| Kepler-51 b | Cold Gas Giant | 45 d | 7.10 R⊕ | 0.20 | 2012 |
| Kepler-51 c | Cold Gas Giant | 85 d | 9.00 R⊕ | 0.27 | 2012 |
| Kepler-51 d | Cold Gas Giant | 130 d | 9.70 R⊕ | 0.34 | 2014 |
| Kepler-51 e | Super Earth | 264 d | — | — | 2024 |
Discovery History
The first planet found here, Kepler-51 b, was discovered in 2012 using the transit method. The most recent addition, Kepler-51 e, followed in 2024.
- 2012 — Kepler-51 b (Transit)
- 2012 — Kepler-51 c (Transit)
- 2014 — Kepler-51 d (Transit)
- 2024 — Kepler-51 e (Transit Timing Variations)
Frequently Asked Questions About Kepler-51
How many planets does Kepler-51 have?
Kepler-51 has 4 confirmed exoplanets. More may await discovery.
Are any planets in the Kepler-51 system habitable?
None of the known planets in Kepler-51 orbit within the star's habitable zone.
How far away is Kepler-51?
Kepler-51 is about 2,557 light-years from Earth in the constellation Cygnus.
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