M 250 @ f9.3 (ag, ST-4)
ST-10XME LRGB 15 minute subs
NGC 3646 is classified as Sc but does not
have the structure of a normal Sc galaxy. While the core area displays the
properties of an Sc galaxy, the outer ring is severely disturbed without uniform
rotation speeds resulting in a wave like structure ( Burbridge, et. al., 1961).