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(IAAC) Obj: M 104 (Sombrero Galaxy) - Inst: 20" f/5 dob newt



Observer: Lew Gramer
Your skills: Intermediate
Date and UT of Observation: 1998-01-01/02, 09:30 UT
Location: Deerfield Township, Ohio, USA (41o N)
Site classification: rural
Limiting magnitude: 6.8 (zenith - through cirrus)
Seeing: 3 of 10 - very good
Moon up: no
Instrument: 20" f/5 Tectron truss-tube dob Newtonian reflector
Magnification: 70x, 210x, 420x
Filters used: None
Object: M104 (Sombrero Galaxy)
Category: Spiral Galaxy [SA(s)absp]
Constellation: Vir
Data: mag 8.0  size 8.7'x3.6'
RA/DE: 12h40m  -11o37m
Description:
My early-rising host alerted me to some unexpected clear skies
this morning at about 4am local time. Jumping out of bed - in
spite of the long drive out here the previous day - I had the
wounded 20" scope out of the barn and ready to observe by 4:30!
My immediate intention was to scan the Virgo Cluster, but the
first target for my short session would be the bright Sombrero.
--
Tracking N from eta Corvi by 2o, I encountered two mag 6 stars:
the first pale orange, then after a degree his yellowish cousin.
Continuing NE about the same distance beyond the N of these, I
hit first a lovely quintuple centered on a bright (mag 7) pair
of yellowish stars. Just beyond I found the striking asterism of
mag 8 stars shaped like the constellation Sagitta, which points
directly at the lovely Sombrero! M104 could immediately be seen
in the same wide field as two parallel, elongated spindles! At
low power (70x), the N bulge was obvious to direct vision, while
the N halo extended some 5'x2'. The halo tapered gradually and
symmetrically on both its E and W ends, and yet ended strangely
in two blunt edges on either side. The S bulge was just visible
to direct vision, although only bright enough in averted vision
to remind me of the photographic view. At a higher power (210x),
both N and S bulges were easy with direct vision, the dark lane
showing as starkly-etched on both sides. The N halo by itself
extended to 6'x2' in a well-defined spindle, the S halo sitting
symmetrically above it elongated 2'x1'. No mottling could be seen
in either of the halos, nor along the pretty dark lane. However,
a stellar nucleus was occasionally noted at high power (420x).
--
This and the string of rapid-fire observations which would follow
this morning (see later posts) proved to be essentially the only
clear skies observations I made this trip, as dire predictions
for NE Ohio's Winter weather proved truer than I could imagine!
And yet, this one group of "barnyard ramblings" in the Realm of
the Nebulae made the whole trip worthwhile astronomically. :)