M 83 Spiral Galaxy


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About this Image

M83 was classified as intermediate between normal and barred spiral galaxies by G. de Vaucouleurs, in his classification this is SAB(s)c. It is showing very well defined spiral arms and displays a very dynamic appearance, appealing by the red and blue knots tracing the arms. The red knots are apparently diffuse gaseous nebulae in which star formation is just taking place, and which are excited to shine by its very hot young stars. The blue regions represent young stellar populations which have formed shortly (i.e., some million or some dozens of million years ago). Between the pronounced spiral arms are regions with fewer stars.
Dark dust lanes follow the spiral structure throughout the disk, and may be traced well into the central region to the nucleus measuring 20" diameter. This nucleus shows strong emission lines. It is composed of an older yellowish stellar population which dominates the whole central region, and extends along the barlike structure.
This galaxy is sometimes called the "Southern Pinwheel". It forms a small physical group, the M83 group, with the peculiar radio galaxy Centaurus A (NGC 5128).

The distance to this galaxy measures 15 million light years.
North is up.
2 asteroids are visible in this image, top right: 146411 (19,3mag) and 88238 (19,1mag) bottom right of the galaxy.

Compare an ESO image of this galaxy: here.

Technical Details


20 " Keller cassegrain in corrected secondary focus at f/9

Mount Liebscher GEM
Camera SBIG STL-11000M at -25C, 8-pos STL filter wheel
Filters Baader LRGB
Date May 02, 2008
Location IAS/Hakos Namibia
Sky Conditions dark skies, raw FWHM 1.5-2.1" temperature 15 C,
Exposure L:R:G:B = 90:30:30:30 minutes (15-minute sub-exposures);
all 1x1.
Programs used Maxim DL 4.5;
Photoshop CS3