Proxima Centauri planet. Artwork of the red dwarf star Proxima Centauri (upper centre), seen from the surface of a hypothetical nearby planet. Proxima Centauri, which lies in the constellation Centaurus, is the nearest star to our Solar System and lies some 4.2 light years from Earth. Red dwarf stars are thought to be the most common stars in the universe. Proxima Centauri is categorised as a flare star, a dim red dwarf star that undergoes random increases in luminosity and radiation emissions because of magnetic activity.