William Herschel discovered NGC 5668 = H II-574 = h1835 on 29 Apr 1786 (sweep 557) and recorded "F, S, lE, r; preceding two very considerable stars." There is nothing at his position, but 1 min 16 sec of RA west is UGC 9363, and the description applies. Because of the poor position, when John Herschel found it again on 9 Apr 1828 (sweep 142) he assumed it was a nova and recorded "vF; pL; R; has a * 15m, nf, involved or very near." In the General Catalogue he equated h1835 with H II-574.

300/350mm - 13.1" (5/26/84): moderately bright, weak concentration, diffuse outer halo of lower surface brightness, moderately large. Two bright stars mag 8.5 SAO 120528 and mag 10 are located 5'-6' NE with a separation of 1.7' N-S. Member of NGC 5668-5746 group (LGG 386).

Notes by Steve Gottlieb