Royal H. Frost discovered IC 3393 = F. 921 on a plate taken on 10 May 1904 at Harvard's Arequipa station using the 24" f/5.6 Bruce photographic refractor. He noted "Elliptical, 0.5' by 0.2' at 125°, bM, magn 14."

600/800mm - 24" (4/28/14): faint, small, elongated 5:3 NW-SE, 25"x15", low even surface brightness. Located 15' ESE of NGC 4438 in the core of the Virgo cluster. IC 3388 lies 6.5' SSW.

Notes by Steve Gottlieb