FreeLists / az-observing / [AZ-Observing] Coma Cluster, JoEr1 and Izzy

[BillFerris@xxxxxxx]

The last two weekends have offered excellent observing under the dark, 
transparent skies of northern Arizona. The following notes are from last 
Saturday's session, which took place at the Doney Mountain Picnic Area 
located on National Forest Service land near Wupatki National Monument. This 
site is a 45-minute drive north of Flagstaff. All observations were made with 
a 10-inch, f/4.5 Meade Starfinder equatorial Newtonian. To see my sketches of 
the following objects, please click on the hotlinks next to the titles.

COMA GALAXY CLUSTER (http://hometown.aol.com/billferris/n48744889.html )
Few sights are as awe inspiring as seeing a true galaxy cluster. To see a 
handful of star cities contained within a single eyepiece field gives one a 
sense of both the vastness and the fragility of the universe. The Coma galaxy 
cluster, located 2.5 degrees west of 4.2 magnitude Beta (43) Comae Berenices, 
lies about 300 million light-years from Earth. MegaStar plots more than 50 
galaxies within a 2-degree radius of the brightest members, NGC 4874 and NGC 
4889. My observation was made with the Meade 8.8mm UWA eyepiece, which 
produces 129x over a 39' diameter field in the Starfinder.

11.6 magnitude NGC 4874 is visible just east of center. Its 2'.5x2'.0 glow is 
aligned east-to-west. A 12th magnitude GSC star marks the spot. NGC 4864, a 
13.6 magnitude class 2 elliptical galaxy, is glimpsed some 5' to the east. 
PPM 102294 stands 6' to the north of NGC 4874. PPM 102295 is another 10' to 
the north. Two faint galaxies are visible northeast of PPM 102294. The first, 
lying 3' from the 7.2 magnitude star, is NGC 4865. NGC 4860 lies another 4' 
along the same line. Both weigh in at a scant 13.6 magnitude.

NGC 4889, an 11.5 magnitude elliptical galaxy, casts a soft glow just 7' west 
of NGC 4874. Its 2'.0x1'.5 form is arranged along a northwest-southeast line. 
13.5 magnitude NGC 4898, 2'.5 to the WSW, blinks in-and-out with averted 
vision. IC 4051 is a 13.2 magnitude elliptical galaxy standing 10' west of 
NGC 4874.

Finally, three galaxies are gathered along the northwest field boundary. 
These include 13.6 magnitude NGC 4881, which lies 5'.5 west of 8.2 magnitude 
PPM 102295. NGC 4885 is a 13.2 magnitude SO-type galaxy positioned 5' WSW 
from NGC 4881. Just inside the northwest field boundary with a 12th magnitude 
GSC star stuck in its side is NGC 4907, a 13.5 magnitude stellar metropolis.

This field presents a good deep-sky challenge for observers with moderate 
aperture under very dark skies, or large aperture under typical rural or 
suburban skies.

JONES-EMBERSON 1 (http://hometown.aol.com/billferris/pk164311.html )
This large, faint planetary nebula is as much a test of your observing site 
as it is of your observing skills. Don't expect to see Jones-Emberson 1 under 
light-polluted skies with any aperture. But under the dark, transparent skies 
of northern Arizona, this gossamer cloud is visible in my 10-inch Newtonian. 
My observation was made at 63x.

Jones-Emberson 1's location is marked by a four-star asterism, which looks 
something like a backwards rendition of Corvus, the crow. This grouping 
stands just east of the planetary. Close inspection reveals the northwest 
corner star of the grouping to be a triple. The star at the southwest corner 
is 9.1 magnitude PPM 31412.

Jones-Emberson 1 (JoEr 1) is visible with the aid of a UHC or OIII filter. 
While the nebula remains unchanged when switching between the two, the UHC 
does show slightly fainter stars. The planetary's 6' diameter glow appears 
uniform and without detail in my 10-inch. Larger scopes reveal bright knots 
within an annulus. A 13th magnitude GSC star peaks through the nebulosity 
along the northern edge of JoEr 1, with an 11th magnitude GSC star another 6' 
to the NNW. 9.0 magnitude PPM 31381 stands sentry to the north. Look for JoEr 
1 about 2.5 degrees northwest of 4.8 magnitude 27 Lyncis.

IZZY (http://hometown.aol.com/billferris/ikzhang051202.html )
Comet Ikeya-Zhang continues to put on a fabulous display. Last Saturday 
night, the comet was in Hercules cruising near the zenith. I caught up with 
Ikeya-Zhang using a 32mm TeleVue plossl, which presents a 1.4 degree true 
field at 36x in my 10-inch.

Izzy's coma was large and bright, some 22' in diameter. The pseudo-nucleus 
appeared bright and slightly elongated along a north-south axis. The western 
portion of the coma was brighter than its counterpart and a gossamer tail 
reached beyond the field horizon to the south. This tail extended at least 
another full eyepiece field in length, which made it about 2.5 degrees long. 
Averted vision suggested the presence of a second tail extending to the SSE 
from the eastern half of the coma. This ghostly veil faded away by the time 
it reached the field boundary.

Regards,

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