Cosmic Scale
Proxima Centauri
Red dwarf · 4.25 light-years
How big is Proxima Centauri?
Proxima Centauri is about 214,600 km across.
See Proxima Centauri in 3D, at true scale
Proxima Centauri is the closest star to the Sun, a small red dwarf gravitationally tied to the bright pair of Alpha Centauri. It is too faint to see with the naked eye despite being our nearest neighbour.
At a glance
| Diameter | 214,600 km |
|---|---|
| Mass | 2.43 × 10²⁹ kg |
| Diameter compared with Earth | 16.8 × Earth |
| Distance | 4.25 light-years |
| Surface | 3,042 K |
| Planets | At least two |
Good to know
- Proxima b orbits in the zone where liquid water is possible — the nearest such planet to Earth that we know of.
- It is a flare star: it can brighten enormously in minutes, which may be bad news for life on its planets.
- Travelling at the speed of Voyager 1, the trip would take about 73,000 years.
- Next smaller: TRAPPIST-1 · 165,900 km
- Next larger: TrES-4b · 250,300 km