NGC/IC Project Restoration Effort

===== NGC 6888 is part of a large oval-shaped HII region (Sharpless 105), brightest along its northeastern side in the red DSS images, and along the northwestern side in blue DSS images. WH's place is supposed to apply to the double star immersed in the northern side of the nebula, but is about +20 seconds and -3 arcminutes off the star. Nevertheless, it is clear from his description in the sweep -- "8 m. Double. A faint milky ray south preceding joins to the double star; it is about 8' long and 1 1/2' broad." -- that the northwestern section is the part of the larger nebula that he saw. Bigourdan's position falls closer to the center of the oval. His descriptions of the field on two nights (he claims to have seen the nebula on only one of them) makes it clear that he did not see WH's object, just two stars near the revised place given in the IC2 notes. It looks like purest coincidence that this is near the center of the HII region.

===== NGC 6888 18" (8/23/03): Using a 6-inch off-axis mask with a 31 Nagler (73x) and an OIII filter, a faint curving arc is visible which begins SW of the mag 7.2 star on the north edge and curves around to the mag 8.2 star on the NE side, extending nearly 90¡ of arc along the annulus of the Crescent Nebula. No other nebulosity was visible. 17.5" (6/29/00): Stunning view at 100x (20mm Nagler) using an OIII filter. The outline appears as a huge, irregular cosmic egg, ~18'x11', floating in a very rich Cygnus star field. The complete annulus is easily visible. The brightest section is along the north side and passes through a mag 7.2 star at the north edge. This piece displays much structure with several knots and wispy tendrils. An isolated bright knot is within the weakly glowing interior and is collinear with the mag 7.2 star and the mag 7.4 central star. The interior has an irregular surface brightness with wispy striations that appear to radiate from the central star towards the NW rim at the end of the bright arc. The rim is widest on the SW end with more nebulosity filling in towards the center. The fine texture and structure of the nebulosity creates a 3-dimensional feel and an "electric" effect. 17.5" (7/5/86): the "Crescent Nebula" is one of my favorite large nebulosities at 100x with a OIII filter (excellent contrast gain). Appears as a bright, 16'x11' oval or egg-shaped annulus elongated SW-NE. The rim is virtually complete except for a small piece of the east side and exhibits a great deal of turbulent, wispy structure. Brightest just SW of mag 7.2 HD 192182 (unequal pair O· 401 = 7.2/10.5 at 14"), which is embedded in the rim at the north end. The nebula also passes through mag 8.2 SAO 69611 on the NE side. Just north of center in the interior is the mag 7.4 Wolf-Rayet star HD 192163 = W-R 136, whose strong stellar wind created this shocked ring-type nebula. This is beautiful nebulosity set in a very rich Milky Way field. 13" (9/11/82): bright, large, oval shell, nearly complete loop visible with UHC, striking unusual appearance! 8" (8/9/80): faint, elongated arc of nebulosity connecting two mag 7.5/8.5 stars and extending SW of the brighter star. Set in a very rich star field. Only the brightest portion at the north end of the nebula was noticed. 80mm finder (6/7/08): using 25x and an OIII filter, the brighter eastern side of the shell was clearly visible and appeared locally brightest in an elongated arc on the north side passing through mag 7.2 HD 192182. A very faint hazy glow with no structure completed most of a large oval.