Heinrich d'Arrest discovered NGC 4451 on 19 Mar 1865 with the 11-inch refractor at Copenhagen. He measured the position on 4 nights and noted the mag 13 star, measured at 83" south.

400/500mm - 17.5" (4/18/87): fairly faint, fairly small, oval NNW-SSE, weak concentration. A mag 13 star is 1.5' S of center. NGC 4445 lies 12' NW.

Notes by Steve Gottlieb