SUPERCEDED-NEWER VERSION AVAILABLE--NGC 7023 - The Iris Nebula in Cepheus
SUPERCEDED-NEWER VERSION AVAILABLE--NGC 7023 - The Iris Nebula in Cepheus
SUPERCEDED-NEWER VERSION AVAILABLE--NGC 7023 - The Iris Nebula in Cepheus
NGC 7023 is a beautiful emission nebula that resembles an Iris flower. The dark areas in this photograph are places where there is cold dust in space. This dust blocks the light from the stars behind it, yielding blank, dark spots in the sky.

In this image, North is Up. This image is cropped to 95% of the original full frame.

Exposure Details
Lens Celestron C-8 SCT with Lumicon telecompressor
Focal Length 1100mm
Focal Ratio f/5.5
 
Mount Schaefer GEM - 7 1/2
Guiding 80mm f/11 guidescope with PHD Guiding
 
Camera Canon 20Da
Exposure 107 subexposures of 180 seconds each at ISO 800 - just under 5 1/2 hours
Calibration 30 darks, 30 flats, 30 bias
 
Date August 5th and 6th, 2011
Temperature 59F on 8/5, 59F on 8/6
SQM Reading
Seeing 4 of 5 on both nights
Location Pine Mountain Club, California
 
Software Used Images Plus 4.0 for camera control, calibration, stacking, digital development, multiresolution sharpening, smoothing and noise reduction. Photoshop CS5 used for levels and curves, color correction, selective color, high pass filter, star shrinking, lab color, saturation adjustments, screen mask invert, and lens correction. Gradient Xterminator for gradient removal. Carboni Tools for additional saturation adjustments, noise reduction, and smoothing. HLVG for additional color correction.
Notes I originally was pretty unsatisfied with this image. However, I eventually reprocessed it and was able to pull out some better colors and nebulosity. Still, I don't think I have the best data, so I plan on reimaging this object someday.

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NGC 7023 - The Iris Nebula in Cepheus