The Kepler-399 System
Kepler-399 is a planetary system in the constellation Cygnus hosting 3 confirmed exoplanets, about 2,415 light-years from Earth.
Size Comparison: The Planets of Kepler-399
Kepler-399: Star and Habitable Zone
Kepler-399
- Surface temperature
- 5,502 K (Sun: 5,772 K)
- Radius
- 0.68 R☉
Habitable zone of Kepler-399: 0.470–1.117 AU (conservative: 0.596–1.059 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 3 Planets in the Kepler-399 System
| Planet | Type | Orbit | Radius | ESI | Discovered |
|---|---|---|---|---|---|
| Kepler-399 b | Terrestrial | 14 d | 0.96 R⊕ | 0.33 | 2014 |
| Kepler-399 c | Super Earth | 27 d | 1.43 R⊕ | 0.36 | 2014 |
| Kepler-399 d | Super Earth | 58 d | 1.89 R⊕ | 0.46 | 2014 |
Discovery History
The first planet found here, Kepler-399 b, was discovered in 2014 using the transit method.
- 2014 — Kepler-399 b (Transit)
- 2014 — Kepler-399 c (Transit)
- 2014 — Kepler-399 d (Transit)
Frequently Asked Questions About Kepler-399
How many planets does Kepler-399 have?
Kepler-399 has 3 confirmed exoplanets. More may await discovery.
Are any planets in the Kepler-399 system habitable?
None of the known planets in Kepler-399 orbit within the star's habitable zone.
How far away is Kepler-399?
Kepler-399 is about 2,415 light-years from Earth in the constellation Cygnus.
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