William Herschel discovered NGC 7566 = H III-185, along with NGC 7554, on 20 Sep 1784 (sweep 279) and logged vF, pS, irr E." His summary description (based on a second observation) mentions "3 faint stars visible in it." Bigourdan measured an accurate position on 7 Nov 1885 (repeated in the IC 2 Notes).

300/350mm - 13.1" (9/29/84): within a triangle of 3 faint stars, elongated ~WNW-ESE, diffuse.

400/500mm - 17.5" (8/1/87): fairly faint, small, oval. Bracketed by two mag 14.5 stars 37" WNW and 27" E of center. Also a mag 14 star is 1.1' SW. Located 13' ENE of NGC 7556 in the NGC 7532-7556 group.

600/800mm - 24" (9/29/16): at 500x; fairly faint or moderately bright, elongated 2:1 NW-SE, ~0.6'x0.3', small bright nucleus. Bracketed by two mag 14.5 stars [27" ESE and 36" WNW of center]. Member of a group with brightest member NGC 7556 13.5' WSW.

Notes by Steve Gottlieb