William Herschel discovered NGC 5233 = H III-425 = h1645 on 3 May 1785 (sweep 407) and noted "vF, vS, may be brought into the field with the two foregoing [NGC 5223 and 5228] and is a little fainter than they are." His position (CH's reduction) is less than 2' southeast of UGC 8668. JH called it "F; S; R: has a vS * near [southeast]."

400/500mm - 17.5" (5/23/98): very faint, small, slightly elongated ~E-W, very small brighter core. A mag 14.5 star is 1.1' SE of center. Located 10' E of NGC 5223 in a group with NGC 5228.

Notes by Steve Gottlieb