William Herschel discovered NGC 1665 = H II-457 = h333 on 5 Oct 1785 (sweep 458) and recorded "F, cL, lbM." On 10 Feb 1830 (sweep 233), John Herschel measured an accurate position and called it "vF, pL, R." NGC 1665 wasn't found on one attempt at Birr Castle and d'Arrest followed up in Oct 1864 with two observations with the 11" refractor at Copenhagen. It was later observed at Birr Castle in 1877.

400/500mm - 17.5" (12/23/89): faint, fairly small, oval SW-NE, weak concentration.

Notes by Steve Gottlieb