The Hercules Galaxy Cluster

The Hercules Galaxy Cluster is a spiral-rich cluster of about 200 galaxies located 500 million light years away across the Northern Local Supervoid. It's part of the Hercules Superclusters, which together with the Coma and Leo Superclusters forms the CfA2 Great Wall, a huge sheet of galaxy clusters that forms one of the largest structures known in the universe. Note the blue jet extending from the core of IC1182, the galaxy near lower right.


Optics/Mount: CPC1100 with f6.3 Celestron reducer on a Milburn Wedge. Dec antibacklash set to 27/27. PEC on.
Camera: SXVR-H694
Exposure: Total exposure time about 6.6 hours; 50 x 5 mins Lum, 10:10:9 x 5 mins R:G:B. All bin 1x1.
Filters: Astrodon Type IIi RGB
Date: Data was collected June 26 to June 28, 2016
Imaging automation and capture: Sequence Generator Pro

Guiding Hardware: ASI120MM, Celestron off axis guider. Guiding scale 0.46 arcsec/pixel. 1 second guide exposures.
Focusing: Rigel Systems GCUSB/nStep on stock C11 focuser
Guiding Software: PHD2. RA aggressiveness 55, hysteresis 0, Minimum Move 1.4 arcsecs, Max RA 200, Max Dec 600. Guiding unbinned with ZWO connection. Dec set to hysteresis. Dithering set to Extreme with Settle < 1.2.
Guiding performance: Generally poor, due to inexperience using gear in the field. FWHM of subs 3.5-4.4 arc seconds, RMS in PHD 1 to 1.3 arcsecs.
Light pollution: Essentially zero. Images were captured from Spruce Knob, West Virginia.
Image scale at capture: 0.6 arcsecs/pixel = f/5.7
Scale of presentation: 1.2 arcsecs/pixel (50% reduction)
Processing: Bias and flats. Stacked and processed with PixInsight, with a few minor modifications in Photoshop.