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(IAAC) Obj: NGC 2467 (The Skull and Crossbones) - Inst: 17.5" f/4.5 dob



Observer: Mike Schexnaydre, Dan Winchell, Lew Gramer; Steve Clougherty
Your skills: Intermediate (some years); Advanced (many years)
Date/time of observation: 19/20 Mar 2001, 04:00 UT
Location of site: ATMoB Clubhouse, Westford MA USA (42oN, 86m elev)
Site classification: Exurban.
Sky darkness: 5.9 <Limiting magnitude>, 5 <Bortle Scale>
Seeing: 5 <1-10 Seeing Scale (10 best)>
Moon presence: None - moon not in sky
Instrument: 17.5" f/4.5 dob
Magnification: 57x, 90x, 125x, 220x
Filter(s): None. UHC. OIII.
Object(s): NGC 2467 (The Skull and Crossbones)
Category: Planetary nebula. Emission nebula.
Class: (Wolf-Rayet object)
Constellation: Pup
Data: mag 9.2m*; size 8'x7'
Position: 075220.8 -262628
Description:
This was my first look at the bizarre and lovely "Skull" from the
light-polluted Northeastern skies of Westford MA. Even up here, it
is a revelation and a joy! Our little observing group spent a good
20 minutes reveling in the details of this relatively huge object.
First impression at 57x without a filter, was of a large, complex,
multi-arced haze surrounding a mag 9 central star.
--
After that impression, we spent much time teasing out the shape of
both the "Crossbones" (which wasn't too hard, in spite of the fact
that this feature is faint) and the "Skull" (considerably tougher,
even though a good part of this area of the object can be observed
with direct vision). At first glance, the Crossbones give quite a
distinctive impression, as two irregularly linear, slightly curved
features running nearly parallel each other, with an intermittent,
irregular dark lane running between them. This impression was most
striking with the 16mm Nagler (125x) coupled to an OIII filter.
--
Interestingly, however, the OIII seemed rather to wash out than to
enhance the much larger "Skull". We generally agreed the best view
of the Skull was also at 125x, but with a UHC filter, not the OIII.
At higher powers, the effects of low altitude began to predominate.
(A Dark Sky filter also enhanced the Skull somewhat better at 125x
than the OIII, though not nearly as well as the UHC at that power.)
--
With a UHC at all powers, dark mottling could be clearly discerned
impinging on the Skull to E and W, as could a somewhat fainter lobe
of nebulosity to the N. And at 125x, the N lobe was more striking,
but the mottlings within the disc of the Skull were less appparent.
Also at 125x in the UHC, the inner area of the Skull disc began to
take on a hint of anularity. At both 90x and 125x, the bright disc
displayed sharp edges to the NE & SW, and diffuse edges elsewhere.
Overall, 125x revealed relatively few additional details vs. 90x.
--
But regardless which eyepiece - or filter, if any - was used, the
Skull was surprisingly HUGE for a nebulous object viewed at such a
low altitude tonight! The two features viewed together with averted
vision and a UHC, filled well over half the field of view of a 16mm
Nagler (125x). This immense, gorgeous beauty is worth adding to your
observing list for next Winter, even if the somewhat obscure Puppis
may be scraping the southern horizon from where you observe!
--
Thanks to Jeanne Clark for pointing out this fine monstrosity to
me in her dob at the Winter Star Party. Naturally in WSP's darker
southern skies, the Skull was even more detailed and fascinating!
--
See a prior (very short) log of the Skull in a 13" by Steve Coe:
http://www.visualdeepsky.org/msg01518.html
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