William Herschel discovered NGC 5123 = H II-666 = h1594 on 9 Apr 1787 (sweep 725) and recorded "pB, S, mbM, iR." JH made the single observation "F; R: gbM; 35"." and measured an accurate position.

400/500mm - 18" (5/30/03): fairly faint, fairly small, round, 0.8' diameter. Just a broad, weak concentration.

Notes by Steve Gottlieb