The Kepler-309 System
Kepler-309 is a planetary system in the constellation Cygnus hosting 2 confirmed exoplanets, about 1,776 light-years from Earth. One of its planets orbits within the habitable zone, where liquid water could exist on a planetary surface.
Size Comparison: The Planets of Kepler-309
Kepler-309: Star and Habitable Zone
Kepler-309
- Surface temperature
- 4,713 K (Sun: 5,772 K)
- Radius
- 0.72 R☉
Habitable zone of Kepler-309: 0.381–0.931 AU (conservative: 0.482–0.883 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-309 System
| Planet | Type | Orbit | Radius | ESI | Discovered |
|---|---|---|---|---|---|
| Kepler-309 b | Super Earth | 5.9 d | 1.56 R⊕ | 0.29 | 2014 |
| Kepler-309 c HZ | Mini Neptune | 105 d | 2.51 R⊕ | 0.65 | 2014 |
Discovery History
The first planet found here, Kepler-309 b, was discovered in 2014 using the transit method.
- 2014 — Kepler-309 b (Transit)
- 2014 — Kepler-309 c (Transit)
Frequently Asked Questions About Kepler-309
How many planets does Kepler-309 have?
Kepler-309 has 2 confirmed exoplanets. More may await discovery.
Are any planets in the Kepler-309 system habitable?
One planet in the system orbits within the habitable zone, where liquid water could exist. Actual habitability depends on atmospheres and composition, which are not yet known.
How far away is Kepler-309?
Kepler-309 is about 1,776 light-years from Earth in the constellation Cygnus.
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