Proxima Centauri is the nearest star to earth, 4.22 light years distant.
’s nearest neighbor, Alpha Centauri, is actually a triple-star system. The system has two bright, closely orbiting stars, called Alpha Centauri A and B, with a distant, dim companion, called Proxima Centauri that is nearly 0.24 light-years or 15,000 AUs from the two other stars.
Of the three stars in the system, Proxima Centauri is the nearest star to , at only 4.24 light years away. The binary appears to the unaided eye as a single star, the third brightest in the night sky, but it lies 4.37 light years from the Sun. Alpha Centauri is located in the Centaurus constellation, which is only visible in the Southern Hemisphere. Proxima Centauri is too faint to the naked eye, with an apparent magnitude of 11.05.
Proxima Centauri is a red dwarf star, about seven times smaller than the sun, or one-and-a-half times bigger than Jupiter. If it’s gravitationally bound to the binary pair, it has an orbital period around the other two of greater than 500,000 years.
Proxima Centauri has been the nearest star for about 32,000 years. It will make its closest approach to the Sun in about 26,700 years, getting to within 3.11 light years of Earth. After 33,000 years, the nearest star will be Ross 248.