Proxima Cen, an M5.5 V star, has 2 confirmed planets.
Measured
Distance
about 4.2 light-years
Star's spectral type
M5.5 V
Confirmed planets
2
How far, from the Sun
About 4.2 light-years. To cross it:
Light4.2 years
Voyager 1's speed74,600 years
Driving at 100 km/h45.3 million years
Voyager 1 at the speed it moved outward over the year to 2026-10-25 (JPL Horizons). Driving: nonstop, never refuelling.
Facts
Proxima Cen d has an equilibrium temperature between −50 and +50 °C.
How it was found
First planet found in 2016, by radial velocity (NASA Exoplanet Archive).
Its planets
Proxima Cen b — 1 times Earth's width (estimated from its mass, not measured), about Earth-sized — probably rocky; its year lasts 11 days; about −55 °C, below freezing; found in 2016 by radial velocity.
Proxima Cen d — 0.7 times Earth's width (estimated from its mass, not measured), smaller than the Earth; its year lasts 5 days; about 9 °C, between freezing and boiling; found in 2025 by radial velocity.
NASA Exoplanet Archive, Planetary Systems Composite Parameters (fetched 2026-11-02). Composite values: where a planet's size or mass was not measured, the archive estimates it from the other.
This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with NASA under the Exoplanet Exploration Program.