Proxima Centauri is a red dwarf star of spectral class M5.5. It is the nearest star to the Sun, located about 4.25 light-years away. Red dwarfs like Proxima Centauri are small, low-mass stars with a cooler temperature (~3,000 K) and lower luminosity compared to the Sun. Proxima Centauri is also classified as a flare star, which means it undergoes sudden increases in brightness due to magnetic activity.