The Kepler-391 System
Kepler-391 is a planetary system in the constellation Cygnus hosting 2 confirmed exoplanets, about 2,835 light-years from Earth.
Size Comparison: The Planets of Kepler-391
Kepler-391: Star and Habitable Zone
Kepler-391
- Spectral type
- K2 III-IV
- Surface temperature
- 5,038 K (Sun: 5,772 K)
- Mass
- 1.27 M☉
- Radius
- 2.88 R☉
- Luminosity
- 4.6000 L☉
- Age
- 4.4 billion years (Sun: 4.6)
Habitable zone of Kepler-391: 1.677–4.048 AU (conservative: 2.124–3.838 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 2 Planets in the Kepler-391 System
| Planet | Type | Orbit | Radius | ESI | Discovered |
|---|---|---|---|---|---|
| Kepler-391 b | Super Earth | 7.4 d | 2.50 R⊕ | 0.20 | 2014 |
| Kepler-391 c | Super Earth | 21 d | 2.88 R⊕ | 0.20 | 2014 |
Discovery History
The first planet found here, Kepler-391 b, was discovered in 2014 using the transit method.
- 2014 — Kepler-391 b (Transit)
- 2014 — Kepler-391 c (Transit)
Frequently Asked Questions About Kepler-391
How many planets does Kepler-391 have?
Kepler-391 has 2 confirmed exoplanets. More may await discovery.
Are any planets in the Kepler-391 system habitable?
None of the known planets in Kepler-391 orbit within the star's habitable zone.
How far away is Kepler-391?
Kepler-391 is about 2,835 light-years from Earth in the constellation Cygnus.
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