William Herschel discovered NGC 3599 = H II-49 = h843 on 14 Mar 1784 (sweep 170) and logged "resolvable, brightest in the middle & the brightness going off imperceptibly." John Herschel wrote on 17 Mar 1831 (sweep 334), "B; R: psmbM; 35"."

400/500mm - 17.5" (4/13/02): moderately bright, moderately large, elongated ~4:3, 2.0'x1.5'. Contains a small, fairly bright round core which is concentrated to the center with a much lower surface brightness halo. Located 21' WNW of NGC 3607 in a group.

Notes by Steve Gottlieb