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(IAAC) Obj: NGC 2261 (Hubble's Variable Nebula) - Inst: 40" f/5 dob





>Subject: NGC 2261 revisited
[NOTE: This is a followup to a previously submitted log of
the same object observed on this same night by Mark. -Lew]

Observer: Mark G. Birkmann
Your skills: Intermediate (some years)
Date/time of observation: 4-4-2000, 1:56 UT, (8:56 CDT)
Location of site: New Haven, Missouri (Lat ~38, Elev ~700 feet)
Site classification: Rural
Sky darkness: 3 <1-10 Scale (10 best)>
Seeing: 3 <1-10 Seeing Scale (10 best)>
Moon presence: None - moon not in sky
Instrument: 40" f/5 dob
Magnification: 408x
Filter(s):
Object(s): NGC 2261 (Hubble's Variable Nebula)
Category: Reflection nebula.
Class: E + R  e1
Constellation: Monoceros
Data: mag ?  size 2' x 1'
Position: RA 06h:39m 12s  DEC +08:44' 00"
Description:
Five months after my last observation of NGC 2261 I was finally able to view it
again. The nebula definitely appears to have changed. Some of these changes are
an overall dimmer appearance, less broad and less extensive base of faint
nebulosity, and a field star that was not seen the second time.
--
These changes could be attributed to different observing conditions and the fact
that drawings probably aren't capable of showing subtle changes such as these
except in the hands of an observer much more experienced than I. Also, I was
feeling a little rushed during this observation.  I started 7 minutes before the
end of astronomical twilight and finished about 45 minutes later just as the end
of the scope was about to hit the wall of the observatory.
--
Some changes, however, I'm pretty confident about.  These include the dark lane
adjacent to the star at the tip, the very bright lane next to the dark lane, and
the central lagoon of faint nebulosity.  The feature I referred to this time as
"the bay" appeared to be a little closer to the edge but was otherwise very
similar to the previous observation.
--
I'm still not entirely sure about the nearly stellar patches in the bright band
but I saw them often enough I felt I should include them in the observation.
I've been looking forward to making this observation all winter because I've
never seen change in a nebula before.  Now I can't wait until next fall to view
it again and see what changes it may have undergone.
--
Clear skies, Mark


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