William Herschel discovered NGC 742 = H II-272 = h173, along with NGC 741, on 13 Dec 1784 (sweep 338). See description under NGC 741. John Herschel logged on 16 Oct 1827 (sweep 95), "The f]ollowing] and fainter of a double neb [with NGC 741]; vF; R; sbM; 12" [diameter]."

On 24 Nov 1854, R.J. Mitchell using the 72" logged a "D neb, the p one is pB, R, bM, the f one is smaller and fainter and lbM." CGCG 413-009 is not labeled as NGC 742.

400/500mm - 17.5" (11/6/93): faint, extremely small, round. Located just off the east edge of NGC 741 in a common halo. Clearly visible, though just 10"-15" diameter.

600/800mm - 24" (12/21/16): at 375x; fairly faint or moderately bright, small, round, 15" diameter, high surface brightness. NGC 742 is 0.8' E of center of NGC 741 (closest companion) and lies near the edge its halo.

Notes by Steve Gottlieb