NASA (Exoplanet Catalog artwork)Proxima Centauri b
The closest exoplanet to Earth, in the habitable zone of our nearest star
Overview
Proxima Centauri b, also referred to as Proxima b, or Alpha Centauri Cb, is an exoplanet orbiting within the habitable zone of the red dwarf star Proxima Centauri in the constellation Centaurus. The host star is the closest star to the Sun, at a distance of about 4.2 light-years from Earth, and is part of the larger triple star system Alpha Centauri. Proxima b and Proxima d, along with the currently disputed Proxima c, are the closest known exoplanets to the Solar System.
Source: Wikipedia
NASA: Proxima Centauri b is a super Earth exoplanet that orbits a M-type star. Its mass is 1.055 Earths, it takes 11.2 days to complete one orbit of its star, and is 0.04848 AU from its star. Its discovery was announced in 2016.
Why it matters
- Discovered in 2016 at just 4.2 light-years; at least 1.07 Earth masses with an 11.2-day orbit.
- Receives similar warmth to Earth, but its flaring red-dwarf star may have stripped its atmosphere.
- Prime target for the Breakthrough Starshot concept of laser-driven probes.
NASA puts it this way: “Proxima Centauri b is a super Earth exoplanet that orbits an M-type star. Its mass is 1.07 Earths, it takes 11.2 days to complete one orbit of its star, and is 0.04856 AU from its star. Its discovery was announced in 2016.”
Discovery & system
- Discovered
- 2016 · Radial Velocity · European Southern Observatory
- Discovery paper
- Anglada-Escudé et al. 2016
- Host star
- Proxima Cen · M5.5 V · 2,900 K · 0.12 M☉
- System
- 2 known planets, 3 stars
- Siblings
- Proxima Cen d
The system
| World | Period | Distance | Radius | Mass | Temp. |
|---|---|---|---|---|---|
| Proxima Cen d | 5.12 d | 0.029 AU | 0.69 R⊕ | ≥ 0.26 M⊕ | 282 K |
| Proxima Cen b | 11.2 d | 0.048 AU | 1.02 R⊕ | ≥ 1.06 M⊕ | 218 K |
By the numbers
- Radius
- 1.02 R⊕6,498 km
- Mass
- ≥ 1.06 M⊕6.3 ×10²⁴ kg · minimum mass (M sin i)
- Orbital period
- 11.2 d0.03 yr
- Distance from star
- 0.048 AU7.25 million km
- Eccentricity
- 0nearly circular
- Equilibrium temp.
- 218 K-55 °C
- Starlight received
- 0.64 × Earth
- Distance from Earth
- 4.2 ly1.3 pc
- Density
- 5.46 g/cm³0.99 × Earth
Sources
Image: NASA (Exoplanet Catalog artwork) · NASA media: generally free of copyright · image page
Text: Wikipedia (CC BY-SA 4.0). Taglines and highlights are editorial.