George Johnstone Stoney, Lord Rosse's assistant, discovered NGC 3189 in January 1850, He recorded "F neby probably extended to the right of [NGC 3190]." The sketch produced by R.J. Mitchell (fig 14, Plate XXVII in the 1861 William Parsons' publication) shows NGC 3189 is the strip of[NGC 3190 on the southwest side of the dust lane. None of the subsequent observations at Birr Castle mention this feature, although d'Arrest claimed an observation with the 11" refractor at Copenhagen on 23 Mar 1865.

900/1200mm - 48" (4/1/11): this number refers to the thin strip of NGC 3190 that parallels the prominent dust lane on the outer southwest edge of the galaxy. This strip has a well-defined southern edge and dims at the southeast end of the galaxy.

Notes by Steve Gottlieb