This is the famous Whirlpool Galaxy in the constellation Canes Venatici, and is one of the best examples of a classic spiral galaxy. Note that this is actually a pair of galaxies: the Whirlpool is the bigger one, and has at least one arm in front of the smaller NGC 5195 to the left, as can be discerned by the dark clouds of dust in that arm silhouetted against NGC 5195. Apparently the two are interacting gravitationally and distorting each other's shape.
Optics 14" f/10 RCOS Ritchey-Chrétien Cassegrain at f/7.5,
Astro-Physics 0.75x Focal Reducer.