William Herschel discovered NGC 4172 = H II-792 = h1123 on 14 Apr 1789 (sweep 920) and noted "F, S, R, bM." His RA is 45 sec too small. JH recorded "pF; S; E; gbM; 15" l, 12" br." and measured an accurate position (in the NGC).

400/500mm - 17.5" (5/13/88): fairly faint, fairly small, bright core, stellar nucleus.

Notes by Steve Gottlieb