The Whale galaxy, NGC 4631 is heavily mottled and appears to be undergoing a great deal of activity. It is intereacting with nearby NGC 4627 which has distorted it and the interaction is likely the source of the activity and a great deal of star formation. The Hockey stick, NGC 4656 and 57 show even more evidence of interaction to my eye.
Details
Date and location - 2010-05-13 at the VCO, Victoria BC
Coditions - Clear, calm, 14 deg C with no moon.
Equipment - QSI-Hyperstar on Meade 14" SCT.
Exposure - 39 light frames - 120s ea plus 10 dark, 10 bias and 10 flat frames for calibration.
Processing in Images Plus.