William Herschel discovered NGC 4668 = H III-663 on 11 Apr 1787 (sweep 726) and logged "vF, S, iF." d'Arrest made two observations and mentioned the triple star that preceded by 12 sec in RA.

400/500mm - 17.5" (2/28/87): fairly faint, fairly small, slightly elongated N-S. Forms a pair with NGC 4666 7.4' NW. A triple star is 3.0' due west consisting of mag 11.5/13/13.5 stars at 20" separation between the closer pairs.

Notes by Steve Gottlieb