AAO image reference DSS 4. « Previous || Next »
Top left is NE. Image width is about 60 arc min.
© 2008, Anglo-Australian Observatory/DSS.
Photograph by David Malin from DSS data.
Alpha Centauri (also known as Rigil Kentaurus) is the nearest bright star to the sun, at a distance of about 4.4 light years. It is also the 4th brightest in the sky. Though it appears to the eye (and in the telescope) as a single point of light, one of the 'Pointers' to the Southern Cross, it is a multiple system of three stars. A fourth star Proxima Centauri appears to be associated with it but is 2 degrees distant on the sky, twice the width of this image.
Alpha is one of very few bright stars that are a similar colour to the Sun. This is not because Sun-like stars are rare, rather it is because they are intrinsically faint. Sun-like stars should also appear white on colour photographs, and the odd range of colours seen here are because an infrared exposure was used to make the picture. Finally, the large coloured halo seen in this image is an artefact due to the scattering of light by the Earth's atmosphere, the telescope optics and the photographic plates, different wavelenghths scattering to different extents.
This picture was made from plates taken in blue-, red- and infrared light with the UK Schmidt telescope. They were digitised by the Space Telescope Science Institute as part of the Digital Sky Survey.
Related image
UKS 38. Proxima Centauri