The Whirlpool Galaxy and its gravitationally-interacting companion. (also a faint edge-on galaxy at far right) Combination of 25 exposures of 200 seconds each, at ISO 3200, with Canon 60Da, through 8″ f/4 Newtonian, at 2013 Oregon Star Party. Captured with MaximDL, guided with PHD, stacked with CCDStack, contrast stretched (e.g. curves) in Photoshop CS6.