 Artist's conception of Proxima Centauri b as a terrestrial exoplanet, with Proxima Centauri and the Alpha Centauri system visible in the background. The actual appearance and composition of the exoplanet beyond this data is currently unknown. | |
| Discovery | |
|---|---|
| Discovered by | Anglada-Escudé et al. |
| Discovery site | European Southern Observatory |
| Discovery date | 24 August 2016 |
| Doppler spectroscopy | |
| Orbital characteristics | |
| 0.04856±0.00030 AU[1] | |
| 11.1868+0.0029 −0.0031 d[1] | |
| 310 ± 50[2] | |
| Semi-amplitude | 1.24 ± 0.07[1] |
| Star | Proxima Centauri |
| Physical characteristics | |
| 0.94–1.4 R🜨[3][a] | |
| Mass | ≥1.07±0.06 M🜨[1] |
| Temperature | Teq: 234 K (−39 °C; −38 °F)[4] |
Proxima Centauri b (or Proxima b),[5] also referred to as Alpha Centauri Cb, is an exoplanet orbiting within the habitable zone of the red dwarf star Proxima Centauri, which is the closest star to the Sun and part of the larger triple star system Alpha Centauri. It is about 4.2 light-years (1.3 parsecs) from Earth in the constellation Centaurus, making it and Proxima d, along with the currently disputed Proxima c, the closest known exoplanets to the Solar System.
Proxima Centauri b orbits its parent star at a distance of about 0.04856 AU (7.264 million km; 4.514 million mi) with an orbital period of approximately 11.2 Earth days. Its other properties are only poorly understood as of 2024[update], but it is believed to be a potentially Earth-like planet with a minimum mass of at least 1.07 M🜨 and only a slightly larger radius than that of Earth. The planet orbits within the habitable zone of its parent star; but it is not known whether it has an atmosphere, which would impact the habitability probabilities. Proxima Centauri is a flare star with intense emission of electromagnetic radiation that could strip an atmosphere off the planet. The exoplanet's proximity to Earth offers an opportunity for robotic space exploration.
Announced on 24 August 2016 by the European Southern Observatory (ESO), Proxima Centauri b was confirmed via several years of using the method of studying the radial velocity of its parent star. Furthermore, the discovery of Proxima Centauri b, a planet at habitable distances from the closest star to the Solar System, was a major discovery in planetology,[6] and has drawn interest to the Alpha Centauri star system as a whole, of which Proxima itself is a member.[7] As of 2023, Proxima Centauri b is believed to be the best-known exoplanet to the general public.[8]
- ^ a b c d Faria et al. 2022, p. 16.
- ^ Anglada-Escudé et al. 2016, p. 439.
- ^ Brugger et al. 2016, p. 1.
- ^ Anglada-Escudé et al. 2016, p. 438.
- ^ Turbet et al. 2016, p. 1.
- ^ Mascareño et al. 2020, p. 1.
- ^ Quarles & Lissauer 2018, p. 1.
- ^ Mieli, Valli & Maccone 2023, p. 435.
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