William Herschel discovered NGC 4596 = H I-24 = h1378 on 15 Mar 1784 (sweep 174) and noted "pB". His RA was 40 seconds too large. John Herschel made 5 observations, first on 9 May 1825 (sweep 4), "B, round, gmbM, 3 small stars follow."

300/350mm - 13.1" (4/16/83): bright, moderately large, bright core, elongated ~E-W. Located about 30' W of mag 5 Rho Virginis.

400/500mm - 17.5" (4/18/87): bright, elongated WSW-ENE, small bright core, possible substellar nucleus. A mag 12.5 star is 1.1' SSE of center at the edge of the halo and two brighter mag 10/11 stars are 3' SE. NGC 4608 lies 19' E.

Notes by Steve Gottlieb