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Alpha, Beta, and Proxima Centauri

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Date:18.8.2004 Time:20:05 UT Exposure:30 min
Field:6.8o x 4.5o Emulsion:Kodak E200 Filter:none
Optics:f=300mm, 1/4.5 Place:Hakos, Namibia Observer:Till Credner

© Copyright by the observers

Alpha Centauri, also called Toliman or Rigil Kentaurus, is the bright white star with 0.3 mag on the left hand side. This triple stellar system contains the closest known stars to our sun. The two main components alpha Centauri A and B (not Beta!) are currently separated by about 15" and can therefore be observed as a double star with a small telescope. In the above wide field photography both stars are hidden in their common glare.

The third star Alpha Centauri C however lies at a distance of about 2 degrees from Toliman. It is actually the closest of the three stars with 4.22 light years to our sun and is therefore called Proxima Centauri. It is a weak M-type red dwarf shining only at 11 mag in the sky. Proxima is gravitationally weakly bound to A and B in a distance of 0.2 lightyears. It takes about a million years for a complete orbit (if it orbits at all).

Magnification of
Proxima Centauri

Jim Kaler on Alpha Cen
Chandra and XMM X-ray observations
ESO interferometry measures stellar diameters of Alpha Cen A and B