Proxima Cen planetary system
Proxima Cen is a cool red dwarf of spectral type M5.5 V approximately 4.2 light-years from Earth (1.30 parsecs). It hosts 2 confirmed exoplanets, of which 1 orbits within the habitable zone where liquid water could exist on a rocky surface.
Host star
- Name
- Proxima Cen
- Spectral type
- M5.5 V
- Effective temperature
- 2,900 K
- Mass
- 0.12 M☉ (solar masses)
- Radius
- 0.14 R☉ (solar radii)
- Distance
- 1.30 pc (4.2 ly)
- Hipparcos catalog
- HIP 70890
Confirmed planets (2)
| Planet | Class | Mass (M⊕) | Radius (R⊕) | Period (d) | Distance (AU) | Eq. temp (K) | Discovered |
|---|---|---|---|---|---|---|---|
| Proxima Cen d | Earth-sized | 0.26 | 0.69 | 5.12 | 0.0288 | 282 | 2025 |
| Proxima Cen b | Earth-sized | 1.05 | 1.02 | 11.18 | 0.0485 | 218 | 2016 |
The planets in detail
Proxima Cen d is an Earth-sized world with about 0.69 Earth radii and 0.26 Earth masses. It orbits Proxima Cen at 0.0288 AU with a 5.1-day year, with insolation of 1.81× Earth's, and a temperate equilibrium temperature of 282 K. It was confirmed in 2025 via radial velocity (Doppler) measurements.
Proxima Cen b is an Earth-sized world with about 1.02 Earth radii and 1.05 Earth masses. It orbits Proxima Cen at 0.0485 AU with a 11.2-day year, with insolation of 0.64× Earth's, and a frigid 218 K equilibrium temperature. Its stellar flux falls within the conservative habitable-zone bounds, though habitability also depends on atmospheric composition, tidal locking, and stellar activity that are not yet measured for this world. It was confirmed in 2016 via radial velocity (Doppler) measurements.
Discovery
The Proxima Cen system was first identified in 2016, with confirmation work continuing through 2025 using radial velocity (Doppler) measurements. Detection facilities: La Silla Observatory, European Southern Observatory.
Observing from Earth
Exoplanets cannot be resolved visually with amateur telescopes — the host star's glare is overwhelming and even space-based direct imaging requires sophisticated coronagraphs. What you can observe is the host star itself at right ascension 217.3935°, declination -62.6762°. Use the 3D orrery above to inspect orbital geometry, planetary scale, and the habitable-zone overlay — the orbits are computed from the published Keplerian elements and animate at user-controlled time rates.
