George Johnstone Stoney, Lord Rosse's assistant, discovered NGC 3185, along with NGC 3187, in January of 1850. He labeled it as Delta on the diagram of the group (shown in the 1861 publication).

Eduard Schönfeld found it at the Mannhein Observatory on 15 Jan 1861, as well as Julius Schmidt at the Athens Observatory on 8 Feb 1861 and Heinrich d'Arrest on 1 Jan 1862 (measuring the position on 5 nights). Schultz referred to it as "Nova Schonfeld", unaware of the Birr Castle observation. John Herschel credited both LdR and d'Arrest in the GC.

200/250mm - 8" (4/24/82): faint, fairly small, elongated.

300/350mm - 13.1" (3/24/84): fairly faint, gradually brighter core.

400/500mm - 17.5" (3/23/85): fairly faint, increases to a brighter core, diffuse halo elongated NW-SE. A mag 14 star is just off the west edge 0.7' from center and a similar star is 1.4' SW of center. Member of the NGC 3190 group = HCG 44.

900/1200mm - 48" (4/18/15): at 610x; very bright, fairly large, oval halo 5:3 NW-SE, ~1.8'x1.1'. Strongly concentrated with a very bright roundish core which increases to a slightly brighter stellar nucleus. The halo has a brighter arcs at the ends of the major axis (northwest and southeast ends) and is slightly weaker inside, creating a weak ring. A very weak bar is highly suspected connecting the ends of the major axis and the core (very subtle barred ring). A mag 14.5 star is just off the west side [42" from center].

Notes by Steve Gottlieb