Terrestrial planet · Proxima Cen

Proxima Cen b

ExoplanetsHabitable-zone candidateDiscovered 2016

Scientific overview

Proxima Cen b is a terrestrial planet orbiting Proxima Cen, completing an orbit every 11 days, about 4 light-years from Earth. It was discovered in 2016 using the radial velocity method.

Host star

Proxima Centauri

Spectral type

M5.5 V

Temperature

2,900 K

Mass

0.122 M☉

Planetary system — Proxima Cen system

View the Proxima Cen system (2 known planets).

Planet	Class	Radius (R⊕)	Period (d)	Distance (ly)
Proxima Cen dRadial Velocity · 2025	Terrestrial planet	0.69	5.1234	4
Proxima Cen bRadial Velocity · 2016	Terrestrial planet	1.02	11.1847	4

Discovery and detection

Detection method

Radial Velocity Method

Discovery year

2016

Habitability notes

Proxima Cen b lies in the habitable zone of its star, the range of orbits where liquid water could in principle exist on a planet's surface. This makes it a candidate of interest for habitability studies — but lying in the habitable zone is not evidence that the planet is habitable or inhabited; its atmosphere and surface conditions remain unknown.

Knowledge connections

Child ofProxima Centauri
OrbitsProxima Centauri
Member of systemProxima Cen system
Discovered by methodRadial Velocity Method
Catalogued inNASA Exoplanet Archive
Habitable-zone candidateHabitable zone
Associated withExoplanet Explorer

Quick facts

Class: Terrestrial planet
Host star: Proxima Centauri
Discovery method: Radial Velocity Method
Discovery year: 2016
Orbital period: 11.1847 d
Semi-major axis: 0.0485 AU
Eccentricity: 0
Radius: 1.02 R⊕
Mass: 1.06 M⊕
Equilibrium temp.: 218 K
Insolation: 0.64 S⊕
Distance: 4 ly

Provenance & sources

review 2026.1

Asteria Scientific Review Process · verification: sourced · accurate

High evidenceconfirmed
Proxima Centauri b is an approximately Earth-mass planet in the habitable zone of Proxima Centauri, the nearest star to the Sun; it was announced in 2016 from radial-velocity measurements.
Source: NASA Exoplanet Science Institute (Caltech/IPAC) — NASA Exoplanet Archive · Freely available; acknowledgement requested
- NASA Exoplanet Archive, NASA Exoplanet Archive

Reviewed by the internal Asteria Scientific Review Process — not an external institutional review. See the evidence framework and authority dashboard.

Scientific citations

Real, source-backed references — primary papers first, then datasets and institutional sources. Formatted through the citation engine; nothing is fabricated.

Peer-reviewed paperA terrestrial planet candidate in a temperate orbit around Proxima Centauri

Guillem Anglada-Escudé & et al. · Nature 536, 437–440 · 2016

Nature · doi:10.1038/nature19106

Cite (APA / BibTeX)

Guillem Anglada-Escudé & et al. (2016). A terrestrial planet candidate in a temperate orbit around Proxima Centauri. Nature 536, 437–440. Nature. https://doi.org/10.1038/nature19106

@misc{cite:anglada-escude-2016,
  title        = {A terrestrial planet candidate in a temperate orbit around Proxima Centauri},
  author       = {Guillem Anglada-Escudé and et al.},
  organization = {Nature},
  howpublished = {Nature 536, 437–440},
  year         = {2016},
  doi          = {10.1038/nature19106},
  url          = {https://doi.org/10.1038/nature19106},
  note         = {Discovery of Proxima Centauri b.}
}

Archive pageProxima Centauri b — NASA Exoplanet Archive

NASA Exoplanet Science Institute (Caltech/IPAC)

Cite (APA / BibTeX)

NASA Exoplanet Science Institute (Caltech/IPAC) (n.d.). Proxima Centauri b — NASA Exoplanet Archive. NASA Exoplanet Science Institute (Caltech/IPAC). https://exoplanetarchive.ipac.caltech.edu/

@misc{cite:exoarchive-exoplanet-proxima-centauri-b,
  title        = {Proxima Centauri b — NASA Exoplanet Archive},
  organization = {NASA Exoplanet Science Institute (Caltech/IPAC)},
  year         = {n.d.},
  url          = {https://exoplanetarchive.ipac.caltech.edu/},
  note         = {Confirmed parameters and discovery references for Proxima Centauri b.}
}

Quality & authority

63%

Reviewed

Completeness: Complete
Source coverage: Complete
Citation coverage: Complete
Relationship coverage: Complete
Review coverage: Complete
Image coverage: None

Data from the NASA Exoplanet Archive. See source quality.

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Planet

Radius (R⊕)

Period (d)

Proxima Cen dRadial Velocity · 2025

0.69

5.1234

Proxima Cen bRadial Velocity · 2016

1.02

11.1847

Habitability notes

Guillem Anglada-Escudé & et al. (2016). A terrestrial planet candidate in a temperate orbit around Proxima Centauri. Nature 536, 437–440. Nature. https://doi.org/10.1038/nature19106 @misc{cite:anglada-escude-2016, title = {A terrestrial planet candidate in a temperate orbit around Proxima Centauri}, author = {Guillem Anglada-Escudé and et al.}, organization = {Nature}, howpublished = {Nature 536, 437–440}, year = {2016}, doi = {10.1038/nature19106}, url = {https://doi.org/10.1038/nature19106}, note = {Discovery of Proxima Centauri b.} }

NASA Exoplanet Science Institute (Caltech/IPAC) (n.d.). Proxima Centauri b — NASA Exoplanet Archive. NASA Exoplanet Science Institute (Caltech/IPAC). https://exoplanetarchive.ipac.caltech.edu/ @misc{cite:exoarchive-exoplanet-proxima-centauri-b, title = {Proxima Centauri b — NASA Exoplanet Archive}, organization = {NASA Exoplanet Science Institute (Caltech/IPAC)}, year = {n.d.}, url = {https://exoplanetarchive.ipac.caltech.edu/}, note = {Confirmed parameters and discovery references for Proxima Centauri b.} }