(IAAC) Obj: Trapezium in M42 - Inst: 60" f/16 Reflector


Observer: Dave Jurasevich
Your skills: Advanced (many years)
Date/time of observation: October 1, 2000 @ 12:00 UT
Location of site: Mt. Wilson Observatory, California (Lat , Elev 5700 ft)
Site classification: Exurban
Sky darkness: 5.7 <Limiting magnitude>
Seeing: 7-8 <1-10 Seeing Scale (10 best)>
Moon presence: None - moon not in sky
Instrument: 60" f/16 Reflector
Magnification: 435x and 685x 
Filter(s): None
Object(s): Trapezium in M42
Category: Multiple star.
Constellation: Ori
Data: mag   size 
Position: RA 05:35.3  DEC -05:23.2
The initial observation was with 4" 100mm Matsumaya eyepiece, observing the
brightest six stars in the Trapezium (components A through F).  Increasing
magnification with a 55mm Televue Plossl (435x) and then a 35mm Panoptic (685x)
it was possible to pick out the two "challenge" stars of the Trapezium, its G
and H components.  H was seen first with the 55mm Plossl as a close double of
about 1 arc-second separation and estimated 280 PA, with both components 
easily held with averted vision and marginally with direct vision.  The 
estimated magnitudes of the H pair was thought to be in the 16-16.5 range.
The G component, although seen with the 55mm Plossl, was a bit easier to 
observe with the 35mm Panoptic and presented itself as an extrememly faint
but "definitely there" pinpoint of light requiring averted vision.  It was
found to lie just S of a diagonal line connecting the A and D components, 
approximately 2/3 the distance from A to D, and was noted to "pop in and out"
of view with varying seeing conditions.  The G component was estimated to be
near magnitude 17 and was the most difficult of the stars to observe.
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