(IAAC) Obj: Abell 83 - Inst: 18" f/4.5 Dob

[anonymous at sedna.atmob.org]

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Observation Poster: John Tatarchuk <tatarjj at auburn.edu>

Observer: John Tatarchuk
Your skills: Advanced (many years)
Date/time of observation: 12/20/06
Location of site: 10 miles west of Fort Davis, TX (Lat , Elev 6000')
Site classification: Rural
Sky darkness: 10 <1-10 Scale (10 best)>
Seeing: 5 <10-1 Seeing Scale (1 best)>
Moon presence: None - moon not in sky
Instrument: 18" f/4.5 Dob
Magnification: 230X
Filter(s): OIII
Object(s): Abell 83
Category: Planetary nebula.
Class: 
Constellation: Cassiopeia
Data: mag 17.6p  size 42"x37"
Position: RA 23h:47.8m  DEC +53:23.9'
Description:
(Probable observation)- this is another real toughie. Its size is 42”x37”,
with a magnitude estimate of 17.6p. I attempted this object on 12/20, a night
that was VERY windy and cut short to about 3-4 hours due to these winds. After
matching the star field to the Aladin Previewer chart at lower power, I popped
in the OIII and increased the power to 230X to try to pull the nebula out of
the background. In adverted vision, I was able to fleetingly acquire an
incredibly faint, small glow just south of a kite-shaped asterism of magnitude
~14 stars. No significant stars were superimposed or interfered with the
object. Unfortunately, I was unable to hold or dependably reacquire the
nebula. However, this object was very near the threshold of what I would
consider “dependably reacquiring”. If I was 99% confident with my Abell 86
observation, then I am 99.5% confident I was able to spot this object. There
is a small chance that a nearby set of two magnitude ~15.5 stars could have
masqueraded as the nebula in adverted vision, however, it’s unlikely because
they are significantly displaced from the object’s position. This one should
be comparatively easy fodder in a 25”.

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