Thread: A Bear Hunt
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Old April 14th 04, 05:41 PM
Bill Ferris
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Default A Bear Hunt

The last few nights have been clear and crisp in northern Arizona. Tuesday
night, I made the 15-mile drive to Anderson Mesa, Lowell Observatory's dark sky
site southeast of Flagstaff, for a short observing session. Two hours later,
I'd made observations and sketches of NGC 2742, NGC 2768, NGC 2841 (all three
are Herschel 400 objects), and the galaxy cluster involving NGC 2767, NGC 2769
and NGC 2771. All can be found in Ursa Major, the great bear, which is well
placed for observing right after sunset.

NGC 2742 (http://members.aol.com/billferris/n2742.html )
I observed this 11.4 magnitude spiral galaxy at 129X in the 10-inch Starfinder
Newtonian. NGC 2742 covers a 3'x1' area along an east-west axis. Its oval form
is highlighted by a slightly brighter core region. The bright star immediately
to the northwest is 7.8 magnitude HD 77726. A trio of 11th through 13th
magnitude stars stands sentry immediately to the west-southwest. 9.2 magnitude
HD 78124 is seen just inside the field boundary, 13' to the east. Eighteen
additional stars complete the view. NGC 2768 is located just beyond the field
of view, some 40' to the southeast. Look for NGC 2742 in the snout of the Great
Bear, about 5 degrees south-southeast from 3.3 magnitude Omicron (1) Ursae
Majoris.

NGC 2768 (http://members.aol.com/billferris/n2768.html )
I observed this 9.8 magnitude elliptical galaxy in my 10-inch Newtonian at
129X. The galaxy is centered and covers an area of 2'.5x2'. The faint outer
region is lost against the night sky. NGC 2768 features a bright stellaring at
the core and is elongated along an east-west line. A 10th magnitude star shines
about 5' due north. A star of similar brightness is seen 4' to the northwest.
9.0 magnitude HD 78297 simmers just inside the edge of the field some 15' to
the northwest of NGC 2768. Another 22 field stars complete the view. You'll
find NGC 2768 about 1.5 degrees south of 5.2 magnitude 16 Ursae Majoris. NGC
2742 is also nearby, just 40' to the northwest.

NGC 2841 (http://members.aol.com/billferris/n2841.html )
Ursa Major is home to several large, bright galaxies. NGC 2841 is among these
but not nearly as well-known as others, particularly those in the Messier
catalog. This 9.2 magnitude Sb-type galaxy was observed at 129X in my 10-inch
Newtonian. Elongated northwest-to-southeast, NGC 2841 covers an impressive
5'x2'.5 area. The inner 2'x1' region appears decidedly brighter and is
punctuated by a stellar core. An 11.1 magnitude star stands alongside the
northwest tip of the galaxy. 8.5 magnitude HD 80566 blazes some 4'.5 to the
east. Eighteen additional field stars provide context. NGC 2841 is located in
far southwestern Ursa Major, about 2 degrees southwest of 3.1 magnitude Theta
Ursae Majoris.

NGC 2767, NGC 2769 & NGC 2771 (http://members.aol.com/billferris/n2767.html )
Galaxy clusters are among my favorite objects to observe. It's astounding to me
that several stellar gothams can be viewed within the same slender patch of
sky. That's like collecting Tokyo, New York City and LA, side-by-side, on the
same patch of land. One such grouping includes NGC 2767, NGC 2769 and NGC 2771,
three galaxies in western Ursa Major. My observation was made at 129X in the
10-inch Starfinder. NGC 2767 is the fainter of the trio, with a blue magnitude
of 14.8. It's slender form is aligned roughly east-west and over a 60"x15"
area. 4' to the east, NGC 2769 emerges as a 60"x30" patch elongated
north-south. This Sa-type galaxy has a blue magnitude of 13.9. Finally, NGC
2771 resides 3' south of NGC 2769. This SBab-type barred spiral presents as a
30" diameter oval, very faint with a blue magnitude of 13.6. All three have
radial velocities of 4820 km per second per megaparsec to 5053 km per sec per
megaparsec, indicating they reside about 250 million light-years from the Milky
Way. Twenty-one stars populate the field. Among these is HD 78792, a 6.7
magnitude star near the eastern field boundary.

Regards,

Bill Ferris
"Cosmic Voyage: The Online Resource for Amateur Astronomers"
URL: http://www.cosmic-voyage.net
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