George Johnstone Stoney, Lord Rosse's observing assistant, discovered two new nebulae in the field of NGC 6173, on 26 May 1849. The 1861 LdR publication mentions "another near" in the entry for NGC 6160, 6173 and 6175. But the 1880 LdR monograph includes a diagram and states, "3 new neb as in diagram, double star suspected in Alpha, Beta faint, Gamma pL & eeF." The three nebulae shown in the diagram are not labeled, but assuming the arrowed direction is west, the configuration fits NGC 6173 (Gamma), the double system IV Zw 63 = PGC 58350 + 58351 (Alpha, shown with two nuclei on the sketch!) to the north, and CGCG 224-047 = PGC 58334 (Beta) due west of the double system. The separations indicated on the sketch are too large -- IV Zw 63 is marked 6' north (actual separation is just under 4') and CGCG 224-047 is marked 8' to its west (actual separation is 4.5'). Two years later (30 May 1851) Bindon Stoney confirmed "Alpha is a double neb, Gamma is vF." Dreyer added the comment "diagram agreeing with the one made in 1849."

John Herschel only included a single LdR nova in the GC based on the note in 1861 publication. In the NGC, Dreyer added a note to NGC 6174, "Second of 3, forming a rectangular triangle, the 2 others being assumed to be h1962 NGC 6173] and h1963 [NGC 6175], but the identity of the group is doubtful." RNGC and PGC identify the double system IV Zw 63 = PGC 58350 + 58351 as NGC 6174 (as here). Harold Corwin and Wolfgang Steinicke favor CGCG 224-047 = PGC 58334, as Dreyer didn't mention NGC 6174 was double. Both assignments, though, are reasonable. See Corwin's notes for more.

400/500mm - 17.5" (7/5/86): very faint, small, slightly elongated, requires averted vision. Located 3.5' N of NGC 6173 in AGC 2197. This is a double system (unresolved).

Notes by Steve Gottlieb