SUPERCEDED-NEWER VERSION AVAILABLE---NGC 6946 - The Fireworks Galaxy on the Border of Cepheus...
SUPERCEDED-NEWER VERSION AVAILABLE---NGC 6946 - The Fireworks Galaxy on the Border of Cepheus...
SUPERCEDED-NEWER VERSION AVAILABLE---NGC 6946 - The Fireworks Galaxy on the Border of  Cepheus...
NGC 6946 is a face on spiral galaxy located on the border of Cepheus and Cygnus. This beautiful galaxy is renowned for having an unusually large number of supernovae, thus earning its title as the "Fireworks Galaxy".

In this image, North is Up. This image is cropped to 54% 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 212 subexposures of 180 seconds each at ISO 1600 - over 10 1/2 hours total
Calibration 30 darks, 30 flats, 30 bias
 
Date August 25, 27, and 28, 2011
Temperature 68F on 8/25, 69F on 8/27 and 8/28
SQM Reading
Seeing 4 of 5 on all 3 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, shadows and highlights, color balance, saturation, high pass filter. Carboni Actions for star saturation adjustments, HLVG for additional color correction.
Notes This is my longest exposure to date, and I think the extra integration time paid off.

This image was chosen Digital Astro Challenge Photo 2nd place for August 2011 in the Galaxy Category. I reprocessed this image in December 2011 to be much improved. This reprocessed version is HERE.

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SUPERCEDED-NEWER VERSION AVAILABLE---NGC 6946 - The Fireworks Galaxy 08/11