Heinrich d'Arrest discovered NGC 571 on 1 Oct 1864 with the 11-inch refractor at Copenhagen. As well as providing an accurate position he measured the mag 14 star that precedes by 6 seconds of RA (or 74" separation), though did not note it was double.

400/500mm - 17.5" (12/23/89): extremely faint, small, round, very diffuse. A close mag 14/15 double star is close west. Located 5.6' SSW of mag 9.0 SAO 54740. NGC 566 lies 15' SW.

Notes by Steve Gottlieb