William Herschel discovered NGC 4643 = H I-10 = h1404 on 24 Jan 1784 (sweep 121) and noted "pB, S." His summary description from 4 observations is "vB, pL, lE, gmbM, 2' l, 1 1/2' br." JH called it "B; S; lE; psbM." and measured an accurate position.

400/500mm - 17.5" (3/24/90): fairly bright, moderately large, oval NW-SE, prominent core. Three mag 11-14 stars lie northwest, the closest is a mag 11.5 star 2.4' NW of center.

Notes by Steve Gottlieb