Proxima Centauri

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Position from Proxima Centauri.

Proxima Centauri is a red dwarf star that is likely a part of the Alpha Centauri star system and is the closest star to the Sun at a distance of 4.22 light-years (3.99×1013 km; 2.48×1013 mi). It is in the constellation of Centaurus.

Proxima Centauri was found to share the same proper motion as Alpha Centauri in 1915 by Robert Innes while he was Director of the Union Observatory in Johannesburg, South Africa.

In 1951, Harlow Shapley said that Proxima Centauri was a flare star. Recorded photographs showed that the star became measurably brighter about 8% of the time, making it the most active flare star then found.

Characteristics[change | change source]

Red dwarfs are usually far too faint to be seen with the naked eye, that means without a telescope. Proxima Centauri has an apparent magnitude of 11 while its absolute magnitude is a very dim 15.5. Even from Alpha Centauri A or B, Proxima would only be seen as a 5th magnitude star.

Proxima Centauri has been the closest star to the Sun for about the last 32,000 years. Barnard's Star will make its closest approach to the Sun around AD 11,700, when it approaches to within about 3.8 light-years.[1] However, at that time, it will not be the nearest star, since Proxima Centauri will then have moved even closer to the Sun.[2]

The size of Proxima Centauri (right) compared to its nearest neighbors.

Related pages[change | change source]

References[change | change source]

  1. García-Sánchez, J. (2001). "Stellar encounters with the solar system". Astronomy & Astrophysics 379: 642. doi:10.1051/0004-6361:20011330. 
  2. Matthews R.A.J. et al. (1994). "The close approach of stars in the solar neighborhood". Quarterly Journal of the Royal Astronomical Society 35: 1–9. 

Other websites[change | change source]