William Herschel discovered NGC 3904 = H II-864 = h3363 on 7 Mar 1791 (sweep 998) and logged "pB, S, R, vgmbM, almost resembling a nucleus." CH's reduction is 2' southwest the center of this galaxy. John Herschel made a single observation, noting "pB, R, psmbM, 15 arcseconds."

200/250mm - 8" (5/21/82): fairly faint, small, slightly elongated, bright core. Located 40' SW of NGC 3923.

400/500mm - 18" (4/29/06): fairly bright, moderately large, elongated 4:3 SSW-NNE. Sharply concentrated with a very bright 20" core and a much fainter halo of uniform surface brightness. NGC 3923 lies 40' NE. Member of a group with NGC 3923, NGC 4105, IC 764 and NGC 4106.

Notes by Steve Gottlieb