William Herschel discovered NGC 4923 = H II-394 = h1518 on 11 Apr 1785 (sweep 396) and recorded "Three, the two following [NGC 4921 and 4923] pretty near each other; the south preceding [NGC 4911] about 8' distance; the time was near that of the two." JH made a single observation and his position is 1.3' too far southwest. d'Arrest made two accurate measurements.

400/500mm - 17.5" (4/21/90): very faint, very small, round, weak concentration. Forms a trio with brighter NGC 4921 2.7' NNW and NGC 4919 is 3.9' SW. Located within AGC 1656.

Notes by Steve Gottlieb