Heinrich d'Arrest discovered NGC 1720 on 30 Dec 1861 with an 11" refractor at Copenhagen. His position (measured on 3 nights) and descriptions matches MCG -01-13-041 = PGC 16485. The RNGC RA is 26 seconds too small.

Based on a photograph taken at the Helwan Observatory with the Reynolds reflector, NGC 1720 was described in the 1935 bulletin as a "spiral in the form of an "S", the central being spindle-lie, 3/4' x 1/4' E 90?, with a pF almost stellar nucleus; there is a slight condensation in the preceding arm and distinct [dust] absorption in the following arm."

300/350mm - 13.1" (12/18/82): fairly faint, moderately large, elongated E-W. Forms a pair with NGC 1726 7' NE. Located 4.8' S of mag 8.1 SAO 131659.

Notes by Steve Gottlieb