William Herschel discovered NGC 3912 = H II-342 = h992 on 6 Apr 1785 (sweep 393) and noted "F, pL." JH made three observations, noting on sweep 343, "pB; pL; R; gbM; 60"." h987 = NGC 3899 is a fourth observation on 26 Mar 1827 with a similar description, but his position was 1.0 tmin west. So, NGC 3912 = NGC 3899, with NGC 3912 the principal designation.

200/250mm - 8" (4/24/82): faint, small, elongated N-S. NGC 3902 lies 23' SSW and NGC 3900 30' NNW.

400/500mm - 17.5" (4/25/98): fairly faint, fairly small, elongated 2:1 N-S, 1.2'x0.6'. Broad concentration with a brighter core but no well-defined nucleus. The surface brightness is irregular at 280x. Sky transparency and seeing conditions poor.

Notes by Steve Gottlieb