(IAAC) Obj: NGC2359; Thor's Helmet - Inst: 56CM, f:4.1, StarMaster

Observation Poster: jim Anderson <madmoon@bellsouth.net>
Observer: jim Anderson
Your skills: Intermediate (some years)
Date/time of observation: 04062002/21:18EST
Location of site: Clark Creek, NC (Lat 35:35:53, Elev Sea Level)
Site classification: Rural
Sky darkness: 8/10 <1-10 Scale (10 best)>
Seeing: 7/10 <1-10 Seeing Scale (10 best)>
Moon presence: None - moon not in sky
Instrument: 56CM, f:4.1, StarMaster
Magnification: 120x, 220X
Filter(s): O-111, UHC
Object(s): NGC2359; Thor's Helmet
Category: Emission nebula.
Class: ?
Constellation: CMa
Data: mag __  size 8.0'
Position: RA 07:17.8  DEC -13:13.4
220X- NGC3259 (Thor's Helmet) also known as 'Duck Nebula' ???
Not much detected with O-111 filter With UHC filter the object resembles a
Snail or Rabbit. After some scrutiny, the wings of the helmet are faintly
visable, from whence the object gets it's popular name. The UHC filter renders
good contrast and is a lot brighter than with the O-111 filter. The dome of the
helmet and the base of the southern wing are readily visable with unfiltered
view, though the object is a featurless greenish glow. I did not observe any color except the pale Blue-Green that is normal for my scoptic vision. The surrounding sky is profuse with 12v mag stars and dimmer. The bright star near
the center of the helmet is a Wolf Rayet star, HD56925 at RA07:18:29.13, 
DEC: -13:13:01.5 at 11.68/11.40v Magnitude. (Morph: !!,vf,wl,viF)
Imagine the dome shape as a snail's shell and at the south end is where the
body of the snail emerges from the shell is a small bright oval knot. The body
arches southward and to the west terminating in very faint branching that
represents the snail's eye stalks. The north area has a very, very faint
nebulous arc to the westward giving the over all impression of a winged helmet.
Inside the NW Quadrent of the dome shape is a companion arc almost concentric
with the outer edge of the dome. Where the inner ars curves back toward the
center is the bright Wolf Rayet star.
The first and lasting impression for me was a ghostly snail in it's shell. 
It is a interesting object that is worthy of concentrated observation and
research. It is a great help to conduct some prior research of NGC2359, so you
have some expectations for a starting point for the observation. I saw it the
evening before this observation with a 30CM SCT under light poluted skies and
it was a disapointing featurless blob without any evidence of wings. With dark
skies and a large aperture NGC3259 is realy a showpiece!
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