Arnold Schwassmann discovered IC 3303 = Sn. 244 on 14 Sep 1900 using a plate taken with the 6" astrograph at the Königstuhl Observatory in Heidelberg. Royal Frost also reported it on a plate taken at the Arequipa station on 10 May 1904. He noted "bM, magn 14 (Sch 244)".

400/500mm - 17.5" (4/25/87): very faint, very small, slightly elongated, can just hold steadily with averted. Located 8.4' WNW of NGC 4388 and 10' SSE of M84 in the central core of the Virgo cluster.

17.5" (1/31/87): very faint, very small, elongated.

600/800mm - 24" (4/28/14): faint to fairly faint, small, elongated 4:3 WSW-ENE, 24"x18". Located 8.3' WNW of NGC 4388.

Notes by Steve Gottlieb