The North American and Pelican Nebulae in Hydrogen Alpha
The North American and Pelican Nebulae in Hydrogen Alpha
The North American and Pelican Nebulae in Hydrogen Alpha
Located in the summer constellation of Cygnus, the North American Nebula (NGC 7000 at the middle left of this image) and the Pelican Nebula (IC 5070 on the right) form a complex of hydrogen emission nebulae located just a few degrees east of the first magnitude star Deneb. Filling over 10 square degrees of sky, the complex shines from the hot hydrogen gas that is energized by the new stars formed in the region. For this reason, the nebulae respond well photographically to a narrow band Ha filter.

Each of the two nebulae contain a distinctive bright feature. In the North American Nebula, the Cygnus Wall runs along "Baja California" within the North American. The Wall is very similar to the bright feature IC 5067 at the northern tip of the Pelican Nebula in that both of these areas contain intense star forming regions. These newly formed stars are shrouded in dust and also illuminate the surrounding nebula.

In this image, North is up. This image is cropped to 80% of the original frame.

Exposure Details
Lens Canon EF 200mm f/2.8L II USM
Focal Length 200mm
Focal Ratio f/3.5
Mount Schaefer GEM - 7 1/2 inch Byers gear
Guiding ONAG On-Axis Guider, Lodestar autoguider, PHD Guiding
Camera Canon 450D - Gary Honis modified (Baader Mod)
Exposure 141 subexposures of 600 sec @ ISO 1600 (23.5 hours) using Astronomik 6nm Ha clip filter
Calibration 15 darks, 30 flats, 30 flat darks, 30 bias
Date June 29, July 2, August 2, August 12, and August 13, 2013
Temperature 71F on 6/29 and 7/2, 57F on 8/2 and 8/12, 65F on 8/13
SQM Reading 21.20 (Bortle 4) on 6/29 and 7/2, 21.30 (Bortle 4) on 8/2, 21.55 (Bortle 4) on 8/12, 20.70 (Bortle 5) on 8/13
Seeing 3/5 on 6/29, 8/2 and 8/13; 4/5 on 7/2, 5/5 on 8/12
Location Pine Mountain Club, California
Software Used Images Plus 5.5 for camera control, calibration, stacking, digital development, smoothing and noise reduction, multiresolution sharpening, and star size and halo reduction. Photoshop CS5 used for levels and curves, high pass filter, star shrinking, screen mask invert, and unsharp mask. Gradient Xterminator for gradient removal. Registar for registration and stack alignment. Carboni Tools for additional noise reduction and smoothing.
Notes This is the deepest hydrogen alpha image I've taken through my Canon 200mm f/2.8 prime lens. While the total exposure time comprises almost a full day of data capturing (23.5 hours), the large amount of data was need to bring the noise level down to a manageable level. Because this data was captured during many warm summer evenings, the camera sensor was fairly noisy.

I'm overall pretty pleased with the comparatively low noise, as it allowed me to bring out some very faint areas of this complex. The structures in this region are very intricate, and I think this image displays these features rather well.