Max Wolf discovered IC 3600 = W. IV-240 on a Heidelberg plate taken 23 Mar 1903. He noted "F, vS, neb *."
400/500mm - 18" (5/12/07): very faint, extremely small, round, 10" diameter. Located to the NE of the core of the NGC 4556 group (29' NE of NGC 4556).
Notes by Steve Gottlieb