NGC2903- Astronomy and astrophotography CCD camera images



12/02/2005
Object name: NGC2903
Popular name:
Object type: Galaxy
Magnitude: 9.6
Size: 12.6 6
Position angle: 1
Classification: SBbc
Apparent RA: 09 32 09.7 Apparent Dec: +21 29 57
Constellation: Leo
Discovered by William Herschel in 1784.
NGC 2903 is another beautiful and more conspicuous Northern objects which Charles Messier missed when compiling his catalog. Thus its discovery was left to William Herschel. This beautiful galaxy was also left out by Patrick Moore when he compiled his Caldwell catalog.
NGC 2905 is a bright knot (star cloud) in NGC 2903. Its not entirely clear on my image - but I think about the 10 oclock position from the centre. Perhaps this feature stands out more when observing visually
NGC 2903 is listed by Brent Tully at a distance of 20.5 million light years. It is a beautiful spiral, seen from an oblique angle. (source seds.org)

Windy night, but very transparent skies with only a sliver of moon. Lately this object has been very popular on QCUIAG, so I thought I'd have a go.
Clouds rolled in before any RGB frames could be exposed.
I was quite shocked at how much galaxy was visible on a raw frame. Click here for a single raw frame. Once stacked, processing was mainly aimed at recovering the outer arms, which are just visible in this image (although you might want to tweek your monitor settings). I could enhance them further, but it would degrade the image by lifting the background noise too high. Also visible is a small unlisted galaxy - the tiny smudge in the bottom right.
Tracking on this image was poor. The camera was rotated slightly to allow this wide target to fit on my CCD chip and the RA axis runs roughly diagonally. The stars form obviously elipses in this direction. I think this was due to a poor choice of guide star. ie too dim.
Overal I was quite pleased with the result, especially the core details - but certainly room for improvement.

Stacked in registax 3 with dark and flat. TIFF exported to photoshop and processed with curves. Star bloat reduced with a less stretched copy over the top. Also exported to IRIS as FITS and RL deconvolution applied. The deconvolved core of the galaxy was applied in photoshop as a feathered L layer over centre of the galaxy to increase detail. The whole deconvolved image is not so useful. Various attempts were made to reduce the background noise, however this was only possible with loss of core detail, and were thus abandoned.

Exposure Details :

IR Block 131x15s on 200mm @ F5 with SC3.5

Curdridge Observatory, Southampton,UK