The Proxima Cen System
Proxima Cen is a planetary system in the constellation Centaurus hosting 2 confirmed exoplanets around 3 stars, about 4 light-years from Earth. One of its planets orbits within the habitable zone, where liquid water could exist on a planetary surface.
Star Proxima Cen and Its Habitable Zone
Proxima Cen
- Spectral type
- M5.5 V
- Surface temperature
- 2,900 K (Sun: 5,772 K)
- Mass
- 0.12 M☉
- Radius
- 0.14 R☉
- Luminosity
- 0.0015 L☉
Habitable zone of Proxima Cen: 0.032–0.085 AU (conservative: 0.041–0.081 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 Proxima Cen System
| Planet | Type | Orbit | Radius | ESI | Discovered |
|---|---|---|---|---|---|
| Proxima Cen b HZ | Terrestrial | 11 d | — | 0.86 | 2016 |
| Proxima Cen d | Terrestrial | 5.1 d | — | — | 2025 |
Discovery History
The first planet found here, Proxima Cen b, was discovered in 2016 using the radial velocity method. The most recent addition, Proxima Cen d, followed in 2025.
- 2016 — Proxima Cen b (Radial Velocity)
- 2025 — Proxima Cen d (Radial Velocity)
Frequently Asked Questions About Proxima Cen
How many planets does Proxima Cen have?
Proxima Cen has 2 confirmed exoplanets distributed around its 3 stars. More may await discovery.
Are any planets in the Proxima Cen 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 Proxima Cen?
Proxima Cen is about 4 light-years from Earth in the constellation Centaurus.
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