NGC/IC Project Restoration Effort

===== NGC 6648 is a double star, Struve 2322. It is also the seventh entry in a short list of "new" nebulae in Struve's "Catalogus Novus ..." of double and multiple stars, hence the "[Sigma] 7" entry in the GC and NGC. Auwers also included it in his list of nebulae discovered by other observers than the Herschels where it is number 41. He says (originally in German; my translation using Google Translate), "Double star of Herschel's class III 8.9 and 11 m, surrounded by a small, oval nebula". He adds in a note "The nebula surrounds [the double star] and aside from a drawing in Catalogue Novus, where it is about 15 [arcsec] long and 8 [arcsec] broad, I could not see anything." Wolfgang has more of Struve's and Auwers's "back stories" in his marvelous 2010 book; those make interesting reading. But this is still just a double star in spite of Struve's mistaken impression that they are immersed in nebulosity, and my mistaken impression in the 1990s that one or two fainter stars are involved.

===== NGC 6648 18" (6/30/11): at this position is a 10" double star (·7) oriented ~E-W with the brighter component on the east side and a difference of ~2 magnitudes. Easily resolved at 175x. Located 9' NNE of mag 6.9 HD 170527.