Heinrich d'Arrest discovered NGC 3875 on 8 May 1864 and noted a double nebula with H III-387 = NGC 3873 at 52" separation in PA 119° (east-southeast). d'Arrest noted the north-preceding nebula was slightly brighter and the south-following nebula extremely difficult. He attached the designation III-387 to the north-preceding object. Dreyer added d'Arrest's "nova" to the GC Supplement (5582), using d'Arrest's mean position (two observations) but mistakenly noted "III-387 sf", instead of "III-387 np". He repeated this error in the NGC, incorrectly crediting d'Arrest with the discovery of NGC 3873, instead of NGC 3875.

300/350mm - 13.1" (2/25/84): very faint, very small. Forms a pair with NGC 3873.

400/500mm - 17.5" (3/12/88): faint, very small, very elongated ~E-W, weak concentration. Forms a close double system with brighter NGC 3873 0.9' NW within AGC 1367.

17.5" (2/20/88): faint, small, oval ~E-W, small brighter core.

Notes by Steve Gottlieb