(IAAC) Obj: Swan Nebula, M17 - Inst: 6" f8 dob, 8" f5 dob, 4" f10 DMG off-axis.

Observation Poster: Shane Sweeney <shane.sweeney@sbcglobal.net>
Observer: Shane Sweeney
Your skills: Intermediate (some years)
Date/time of observation: 07/06/05 0500 UT
Location of site: Inola, OK (Lat 36.14, -95.45., Elev 300m)
Site classification: Exurban
Sky darkness: 5.45 <Limiting magnitude>
Seeing: 8.7 <1-10 Seeing Scale (10 best)>
Moon presence: None - moon not in sky
Instrument: 6" f8 dob, 8" f5 dob, 4" f10 DMG off-axis.
Magnification: 29, 50, 80, 100, 120, 250
Filter(s): DMG Narrow Band Pass
Object(s): Swan Nebula, M17
Category: Emission nebula.
Constellation: Sag
Data: mag 6.0  size 11'
Position: RA :  DEC :
The skies were unusually calm and transparent for this exurban site.
The milky way stood out starkly with dark lanes, M8, M22, and M10, easily
apparent with direct naked eye observation.
4" f10 instrument is an unobstructed reflector, M17 at 29x is quite bright sitting well framed in surrounding star field. At low mag this high contrast scope gave the next best wide view of M17 we had tonight. At 80x view was
still very acceptible with added detail and some subtle festooning.
Adding the narrow band filter to this view darkened the field a bit too much.
The 6" scope as a traditional wooden Dob that give superior views at 35x it gave a nice bright "check mark" veiw of this nebula when we added the filter detail jumped out at us and extended off the FOV to the east. The best wide field view was from the 8" homemade Dob using a 2" 32mm Erfle occular M17 was a pretty white whisp of bright nebulosity surrounded by innumerable  stars and
its friend M18 an open star cluster. The 8" at 100x with the filter showed more detail than was casually apparent.     
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