AAO image reference UKS 38. « Previous || Next »
Top left is NE. Image width is about 25 arc min. Mouseover for time-separated colour images
© 2002, Anglo-Australian Observatory/Royal Observatory, Edinburgh.
Photograph by David Malin from DSS data.
Proxima Centauri is the nearest known star to the sun, at a distance of about 4.2 light years. It is an intrinsically faint red star, more than ten magnitudes (ten thousand times) fainter than the Sun. It is also much cooler, with a surface temperature of about 3100 C. Its visual (apparent) magnitude is eleven, so it is only visible with a good telescope, and only then from southern latitudes. Proxima is about one-tenth the mass of the sun, which accounts for its low surface temperature. It is possibly an outlying member of the triple alpha Centauri system just a few light days closer to us than the other, much brighter stars in the group.
Because it is so close Proxima has a large 'proper motion', moving against the multitudes of background stars by 3.85 arc seconds a year, enough to carry it the width of the full Moon in about 500 years. The monochrome plates from which this 3-colour picture were made were taken in 1976 (blue), 1982 (red) and 1993 (green), and the images of Proxima have been aligned to show the redness of the star. Mouseover this image to see the star as separate coloured images showing its movement over 17 years (AAO image reference UKS 38a). The faint reddish halo around the star is an artefact of the infrared plate.
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
DSS 4. Alpha Centauri