William Herschel discovered NGC 4123 = H V-4 = h1092 on 23 Feb 1784 (sweep 158) and recorded "vF, of a considerable extent, being about 5 or 6' diameter. To the north of the nebula at a distance of about 15' or more is a bright triangle of stars, the base where of is towards the nebula." His position and description matches UGC 7116 = PGC 38531.

R.J. Mitchell, observing on 29 Mar 1856 at Birr Castle, noted "the n one [NGC 4123] is however a spiral like an "S", the arms being faint."

400/500mm - 17.5" (3/28/87): fairly bright, fairly large, elongated 3:2 NW-SE, 3'x2', small bright core. NGC 4116 lies 14.1' SW.

Notes by Steve Gottlieb