William Herschel discovered NGC 533 = H II-462 = h121 on 8 Oct 1785 (sweep 462) and logged "pB, R, pL, mbM." On 20 Dec 1786 (sweep 655) he noted "pB, R, vgbM, about 1.5' dia." and on 3 Dec 1787 (sweep 788), "F, S, R, gbM." John Herschel recorded on 16 Dec 1827 (sweep 110), "B; pL; R; bM."

200/250mm - 8" (1/1/84): very faint, very small, weak concentration. A mag 13.5 star is 3.5' WNW.

300/350mm - 13.1" (1/1/84): moderately bright, bright core, faint stellar nucleus suspected, elongated halo WSW-ENE. A mag 13.5 star is 3.4' WNW.

600/800mm - 24" (9/23/17): at 375x; bright, large, oval 3:2 SW-NE, ~2.5'x1.6', sharply concentrated with a large bright core that is slightly elongated, halo gradually fades into the background sky. NGC 521 lies 14' WSW and IC 103/105/109 is ~20' NNW.

Notes by Steve Gottlieb