NGC 253 - The Silver Dollar Galaxy in Sculptor
NGC 253 - The Silver Dollar Galaxy in Sculptor
NGC 253 - The Silver Dollar Galaxy in Sculptor
NGC 253 is the largest galaxy in the Sculptor group of galaxies. Visually, the galaxy is quite large - about 28' x 6'. This is the width of the full moon (although much fainter and thinner!). At magnitude 8, it is a fairly easy object to see in a telescope, although it is always quite low for us in the Northern Hemisphere.

In this image, North is Up. This image is cropped to 94% of the original full frame.

Exposure Details
Lens Celestron C-8 SCT with Celestron focal reducer
Focal Length 1260mm
Focal Ratio f/6.3
Mount Schaefer GEM - 7 1/2
Guiding 80mm f/11 guidescope with PHD Guiding
Camera Canon 20Da
Exposure 54 subexposures of 150 seconds each plus 28 exposures of 300 seconds each at ISO 1600 - about 4 1/2 hours total exposure
Calibration 30 darks, 30 flats, 30 bias
Date September 26 and 27, 2011
Temperature 59F on 9/26, 51F on 9/27
SQM Reading
Seeing 3 of 5 on both nights
Location Pine Mountain Club, California
Software Used Images Plus 4.0 for camera control, calibration, stacking and digital development. Photoshop CS5 used for flat fielding , curves, color Correction and saturation adjustments, star shrinking, and high pass filter. HLVG for additional color correction, Carboni Actions for additional saturation adjustments.
Notes This was a difficult object to photograph because it never rises above 30 degrees at my latitude. I think the final result came out rather well. I have some Hydrogen Alpha data to add to this when time permits.

An earlier processing version of this image (not as good) was chosen Digital Astro Challenge Photo 1st place for September 2011 in the Galaxy Category. This earlier version is HERE.

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SUPERCEDED-NEWER VERSION AVAILABLE---NGC 253 - The Silver Dollar Galaxy in Sculptor