NGC 7640 is an edge on warped spiral discovered by William Herschel.
Details -
2016-12-01
20" f/4.1 telescope at the SDG observatory of Garry Sedun in Arizona.
TV Paracorr coma corrector and SBIG ST2000 XM camera.
Guidescope WO 80mm f/6.8 APO.
Mount - Paramount ME
Exposures - 240 s subs - 3L and 2 each of BGR with darks, flats and bias frames to match.