This 3-hour image depicts the vast area of nebulosity surrounding the star Gamma Cygni (the large star in the center of the image, which is the center star in the cross beam in the Northern Cross). I used a hydrogen-alpha filter that transmits radiation only through a 7 nanometer "window" surrounding the principal hydrogen-alpha wavelength of 656 nanometers. Theoretically, this filter should block out virtually all forms of radiation other than the hydrogen-alpha wavelength associated with most nebulae, including light pollution and glare of the Moon. The Moon was about 70% illuminated when I took this image, and so this was an excellent test of the quality of the filter. Incredibly, it blocked out virtually all extraneous light, including the bright glare of the nearly full Moon.
Also of interest in this image is the small star cluster NGC 6910 to the right of Gamma Cygni.
The Gamma Cygni Nebula
Date Taken:October 7, 2011
Location Taken: Conditions of Location:FWHM 1.8
Equipment Used:Takahashi FSQ-106 apochromatic refractor telescope, Paramount ME mount, SBIG STL11000 CCD camera with remote guide head connected to Takahashi Sky90 for autoguiding, Astrodon hydrogen-alpha filter, T-Point used for polar alignment (required for each imaging session due to my portable setup).
Processing Used:12 x 15 minutes using a hydrogen-alpha filter, guided exposure (total exposure time of 3 hours), 1x1 binning, processed in Maxim DL and Photoshop.
Distance from Location: Constellation:Cygnus (the "swan")
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