The Kepler-221 System
Kepler-221 is a planetary system in the constellation Cygnus hosting 4 confirmed exoplanets, about 1,257 light-years from Earth.
Size Comparison: The Planets of Kepler-221
Kepler-221: Star and Habitable Zone
Kepler-221
- Surface temperature
- 5,243 K (Sun: 5,772 K)
- Radius
- 0.82 R☉
Habitable zone of Kepler-221: 0.523–1.253 AU (conservative: 0.663–1.188 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-221 System
| Planet | Type | Orbit | Radius | ESI | Discovered |
|---|---|---|---|---|---|
| Kepler-221 b | Super Earth | 2.8 d | 1.71 R⊕ | 0.27 | 2014 |
| Kepler-221 c | Mini Neptune | 5.7 d | 2.93 R⊕ | 0.22 | 2014 |
| Kepler-221 d | Mini Neptune | 10 d | 2.73 R⊕ | 0.24 | 2014 |
| Kepler-221 e | Mini Neptune | 18 d | 2.63 R⊕ | 0.28 | 2014 |
Discovery History
The first planet found here, Kepler-221 b, was discovered in 2014 using the transit method.
- 2014 — Kepler-221 b (Transit)
- 2014 — Kepler-221 c (Transit)
- 2014 — Kepler-221 d (Transit)
- 2014 — Kepler-221 e (Transit)
Frequently Asked Questions About Kepler-221
How many planets does Kepler-221 have?
Kepler-221 has 4 confirmed exoplanets. More may await discovery.
Are any planets in the Kepler-221 system habitable?
None of the known planets in Kepler-221 orbit within the star's habitable zone.
How far away is Kepler-221?
Kepler-221 is about 1,257 light-years from Earth in the constellation Cygnus.
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