William Herschel discovered NGC 6155 = H II-690 on 12 May 1787 (sweep 735) and recorded "F; pL; gbM; iF." His position is 37 sec of RA too large. He logged this galaxy again on 13 Apr 1788 (sweep 832) and noted "eF, S, iF." His RA on this sweep was 17 sec too large. Bigourdan's measured an accurate position on 29 May 1884 (repeated in the IC 2 Notes).

400/500mm - 17.5" (7/1/89): moderately bright, fairly small, elongated NW-SE, broadly concentrated halo. Located equidistant from two double stars; a mag 9.5/12.5 at 30" separation is 3.2' SW and an evenly matched mag 14 pair at 12" separation is 3.3' E.

Notes by Steve Gottlieb