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> The proper motion of Proxima Centauri

The proper motion of Proxima Centauri

author: Anglo-Australian Observatory/David Malin Images/Novapix

reference: a-eto01-00102

Image Size 300 DPI: 51 * 40 cm

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) showing its movement over 17 years. The faint reddish halo around the star is an artefact of the infrared plate.

Keywords for this photo:

AAO - ASTRONOMY - CENTAURUS - DWARF - FLARE STAR - M STAR - MOVEMENT - POSTER - PROXIMA CENTAURI - RED DWARF - SIDING SPRING - SOUTHERN HEMISPHERE - STAR -