William Herschel discovered NGC 5533 = H II-418 = h1766 on 1 May 1785 (sweep 405) and noted "pB, mbM, iR." JH made three observations. His positions vary by nearly 3' in declination, but his position on sweep 71 is accurate. On an observation at Birr Castle by Mitchell on 30 Mar 1856, he noted "E nearly north-south, small star south-following, B Nucl."

CGCG misidentifies CGCG 191-070 as NGC 5533.

200/250mm - 8" (4/24/82): faint, elongated SW-NE, broad concentration. Located 25' SW of a mag 5 star.

300/350mm - 13.1" (6/18/85): fairly bright, moderately large, elongated SW-NE, small bright core, diffuse halo.

Notes by Steve Gottlieb