William Herschel discovered NGC 6166 = H II-875 = h1961 on 30 May 1791 (sweep 1015) and recorded "pB, S, lE, vgmbM." His position is poor - roughly 20 seconds of RA too far west and 3' too far north. JH made the single observation "F; S; R." and measured an accurate position. See Harold Corwin's identification notes for a discussion of the close companions and the letter designations.

300/350mm - 13.1" (5/26/84): fairly faint, fairly small, slightly elongated. Brightest and largest in A2199. Several faint companions are near.

400/500mm - 17.5" (8/1/92): fairly faint, fairly small, elongated 4:3 SW-NE, broad concentration. Brightest and largest of seven galaxies in AGC 2199 within a 5' circle! The following close companions were viewed: NGC 6166A = MCG +07-34-050 2.3' SW, NGC 6166B = MCG +07-34-076 2.9' E, NGC 6166C = MCG +07-34-048 3.1' NW, NGC 6166D = MCG +07-34-056 2.0' S, MCG +07-34-064 4.8' SSE and an anonymous galaxy just off the south edge of NGC 6166.

Notes by Steve Gottlieb