IC 5146 - The Cocoon Nebula in Cygnus
IC 5146 - The Cocoon Nebula in Cygnus
IC 5146 - The Cocoon Nebula in Cygnus
IC 5146 is an emission and reflection nebula. The stars contained within the nebula are newly formed stars. There is a dark lane that runs from the nebula towards the upper right of the image.

In this image, North is Up. This image is cropped to 86% 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 183 subexposures of 180 seconds each at ISO 1600 - over 9 hours total
Calibration 30 darks, 30 flats, 30 bias
Date September 1, 2 and 3, 2011
Temperature 60F on 9/1, 62F on 9/2, 63F on 9/3
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, digital development, and smoothing. Photoshop CS5 used for levels and curves, color correction, saturation adjustments, star shrinking, noise reduction, and high pass filter. Carboni Actions for additional saturation adjustments, noise reduction, and smoothing. Gradient Xterminator used for gradient removal.
Notes IC 5146 is a very subtle object, so I gave it a lot of exposure time. The processing was pretty tricky, particularly because of a bad gradient from my Canon 20Da camera. Nonetheless, I think the final photo shows the object rather well.