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(IAAC) Obj: IC 421 - Inst: 17.5" f/4.5 dob



Observer: Lew Gramer
Your skills: Intermediate (some years)
Date/time of observation: 9/10 Feb 1999  05:00 UT
Location of site: MIT Haystack Obs., Westford, MA, USA (Lat 43N, Elev 30m)
Site classification: Exurban
Sky darkness: 6.6 <Limiting magnitude>
Seeing: 4 <1-10 Seeing Scale (10 best)>
Moon presence: None - moon not in sky
Instrument: 17.5" f/4.5 dob reflector
Magnification: 57x, 225x
Filter(s): None
Object(s): IC 421
Object category: Galaxy
Object class: SAB(rs)bc
Constellation: Ori
Object data: mag 15  size 3.24x2.75 80o
Position: 053208.5-075504
Description:
This is a strange IC galaxy - unusual first of all because it IS a galaxy
deep in the bowels (literally) of Orion, amid the Winter Milky Way. What's
more IC 421 is plotted in my AstroAtlas, but not in GUIDE - even though it
is in the GUIDE database! At any rate, DSS clearly shows it as a graceful,
small spiral, only slightly inclined. I began my hop to IC 421 by sweeping
S from the "delicately placed" mag 4.5 star upsilon Ori, using a pair of
mag 6 stars immediately to the W (forming a nice right triangle with and
nearly in the same wide-field with it) as "pointer" stars aiming SE. After
locating the galaxy with difficulty (it can be quite tricky for observers
up North due to its low, low surface brightness), I immediately went to a
much higher power (225x), as nothing at all could be distinguished in this
averted vision "dot" at 57x. I found even at high power that IC 421 seemed
far smaller than its cataloged size. But I could also now discern that it
was elongated NE-SW, with approximately 3-to-5 elongation. This too was in
conflict with the cataloged inclination of 80o - nearly face-on! But with
careful averted vision, the reason for this became clear: I was viewing a
much brighter knotting of details which swept above and below the intense,
bright inner core. After a few minutes concentration, I saw hints of other
detail both in the SE area of the halo, and especially in the outer core.
(A later look at a Palomar DSS image confirmed both the face-on nature of
i421, as well as these details.) Worth a look, especially in the South!
--
Object data thanks to dObjects: http://www.eaglequest.com/~bondono/dObjects
Galaxy morphology thanks to NASA Extragalactic Database (NED)


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