John Herschel discovered NGC 5666 = h1834 on 9 May 1825 (sweep 4) and recorded "vF; R; 10". Stellar; hardly distinguishable from a star." His position was accurate. This is only his 4th deep sky discovery.

400/500mm - 17.5" (3/12/94): fairly faint, small, round, 40" diameter, fairly high surface brightness, weak concentration. A mag 10.5 star is 5.0' N.

Notes by Steve Gottlieb