|NGC 7635 "Bubble Nebula": Emission Nebula (Cassiopeia) RA: 23h 20.7m / DEC: +61° 12'.0|
Instrument: 10-inch Starfinder
If you're observing M52 and the transparency seems as good as it gets from your site, slew southwest about 43' to 7.0 magnitude HD 220057. Look for 9.0 magnitude SAO 20575 about 6' to the east. If you notice a subtle haze around that star, you've found NGC 7635, the Bubble Nebula. The sketch at left captures the view in my 10-inch Starfinder Newtonian at 129X. An OIII filter is used to enhance contrast.
HD 220057 is nearly centered in the drawing. NGC 7635 runs northwest-to-southeast across a 14'x4' area. It appears brightest around SAO 20575, the 9th magnitude star mentioned above. This is an extremely delicate nebula. The greater portion, visible with averted vision, extends northwest from SAO 20575 for a distance of about 9', terminating near a faint double star. A 4' stretch of the nebula reaches southeat to 10th magnitude GSC 4279:0219. The namesake feature of this emission nebula is not visible in the 10-inch. Fifteen additional field stars frame the view.
Layout, design & revisions © W. D. Ferris
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Revised: July 28, 2004 [WDF]