William Herschel discovered NGC 5582 = H II-754 = h1786 on 29 Apr 1788 (sweep 837) and recorded "pB, pL, R, a faint nucleus." JH made four observations and first described it (sweep 73) as "pB; R; gbM; 30"; has a * 11m 50° sp, dist 80"."

400/500mm - 17.5" (6/23/01): fairly faint, moderately large, elongated 3:2 SSW-NNE, ~1.6'x1.1'. Embedded in the halo is a small, rounder, prominent core ~35" diameter. The core is moderately concentrated to a quasi-stellar nucleus. Situated with a group of stars including a mag 10.5 star 3.5' SE, a mag 13 star 1.5' WSW and a mag 14 star 1.2' following.

17.5" (5/19/01): moderately bright, moderately large. The halo is 1.5'x1.0' extended SSW-NNE and contains a prominent core which increases to a stellar nucleus. Located 3.7' NW of mag 10 SAO 64089 within a small group of stars including a mag 13 star 1.5' SW of center.

Notes by Steve Gottlieb