The Kepler-166 System
Kepler-166 is a planetary system in the constellation Cygnus hosting 3 confirmed exoplanets, about 1,968 light-years from Earth.
Size Comparison: The Planets of Kepler-166
Kepler-166: Star and Habitable Zone
Kepler-166
- Surface temperature
- 5,350 K (Sun: 5,772 K)
- Mass
- 0.88 M☉
- Radius
- 0.83 R☉
- Age
- 4.5 billion years (Sun: 4.6)
Habitable zone of Kepler-166: 0.547–1.307 AU (conservative: 0.693–1.239 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-166 System
| Planet | Type | Orbit | Radius | ESI | Discovered |
|---|---|---|---|---|---|
| Kepler-166 b | Mini Neptune | 7.7 d | 2.27 R⊕ | 0.26 | 2014 |
| Kepler-166 c | Mini Neptune | 34 d | 2.38 R⊕ | 0.35 | 2014 |
| Kepler-166 d | Super Earth | 1.6 d | 1.73 R⊕ | 0.27 | 2016 |
Discovery History
The first planet found here, Kepler-166 b, was discovered in 2014 using the transit method. The most recent addition, Kepler-166 d, followed in 2016.
- 2014 — Kepler-166 b (Transit)
- 2014 — Kepler-166 c (Transit)
- 2016 — Kepler-166 d (Transit)
Frequently Asked Questions About Kepler-166
How many planets does Kepler-166 have?
Kepler-166 has 3 confirmed exoplanets. More may await discovery.
Are any planets in the Kepler-166 system habitable?
None of the known planets in Kepler-166 orbit within the star's habitable zone.
How far away is Kepler-166?
Kepler-166 is about 1,968 light-years from Earth in the constellation Cygnus.
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