Instrument

12.5" RCOS @  ~f/9 (2880 mm fl) 0.64 arcsec / pixel.  Shown resampled to 1.67 arcsec / pixel.

Mount

Paramount ME

Camera

SBIG STL-11000 w/ internal filter wheel, AstroDon Filters

Acquisition Data

4/30/2009 to 5/30/2009  Chino Valley, AZ

Exposure

Lum    375 min (25 x 15 min, bin 1x1)

RGB    360 min (  8 x 15 min each, bin 1x1)

Software

CCDSoft, CCDStack, Photoshop CS3 w/ the Fits Liberator plugin, Noel Carboni's actions and Russ Croman's Gradient Exterminator

CCDStack to register, normalize, data reject and combine sub exposures.

PhotoShop for the stretching, color combine and sharpening

Comment

North is ~ to the top, the image is rotated 35 deg's CW

Abell 2151, The Hercules Cluster, contains about 100 galaxies and is at a distance of about 500 million light years. The cluster is part of the larger Hercules supercluster, which is then, part of the much larger Great Wall super-structure. Abell 2151 is loaded with star forming spiral galaxies and relatively few older elliptical galaxies.