The Hercules Galaxy Cluster (Abell 2151) is a cluster of about 200 galxies some 500 million light-years distant in the constellation of Hercules. It is rich in spiral galaxies and shows many interacting galaxies.
The bluish, nearly edge-on glaxy in the center of the image is NGC 6045A shining at 14.8 mag, the two interacting spiral to the right are NGC 6050A/B. Further to the right, IC 1182, shows a blue tidal tail and shell of evidently accreted stars and gas.
Telescope: RCOS 20" f/8.5
Mount: Paramount ME
Detector: Apogee U16M
Filters: Astrodon Gen 2
Exposures: LRGB 660:240:240:240 min
Observatory: Sierra Remote, California