FreeLists / az-observing / [AZ-Observing] The Mice and Other Deep-sky Rodents

[BillFerris@xxxxxxx]

Motivated by the recently released images from a refurbished and "better than 
new" Hubble Space Telescope, I observed several challenging DSOs Saturday 
night (Cinco de Mayo UT). Among these were the Mice (NGC 4676), NGC 5053 and 
Abell 39.

NGC 4676 is a pair of interacting galaxies in Coma Berenices. They're huddled 
along the border with Canes Venatici about 1.5 degrees south-southeast of NGC 
4656, popularly dubbed the Hockey Stick. NGC 4676 appears as a subtle 
irregular patch in my 10-inch, f/4.5 Newtonian at 129x. Bumping up the 
magnification to 190x (Meade 18mm SWA w/ TeleVue 3x Barlow), they separated 
into the two galaxy cores.

The southern galaxy's core covers a 60"x30" area and is aligned roughly 
east-west. A 10th magnitude GSC star shines 5'.6 due east. The northern 
galaxy's core is larger, 60"x45", aligned north-south and centered about 75" 
northwest of its companion. These are faint little stinkers with Vmags in the 
mid-13s by my estimate. Does anyone know of definitive Vmags for the Mice?

NGC 5053 has been a thorn in my side for several years. Last night, I made my 
first observation of this faint globular cluster. It's located in Coma 
Berenices about 58' southeast of larger, brighter M53. According to Skiff, 
NGC 5053 has an integrated visual magnitude of 9.0 and is 9'.0 in diameter. 
This suggests a surface brightness of about 22.4 magnitude per square 
arcsecond, not bright but not faint. This should be a fairly trivial 
observation in most scopes but previous attempts have always proved 
frustrating.

My sketch from last night reveals the following: Both globular clusters are 
visible at 36x in the 10-inch. Applying 82x, NGC 5053 appears as an 8' 
diameter haze of light, very delicate to the eye. 7.7 magnitude PPM 129701 
stands 24' due south. The gauzy globular is flanked by a pair of moderately 
bright stars, 9th magnitude GSC 1454:692 residing 6' to the southeast and an 
11th magnitude GSC 1454:802 glowing 8' to the southwest. A handful of faint 
foreground(?) stars decorate the face of the cluster.

Abell 39 is featured in an article by Eric Honeycutt in the May issue of "Sky 
& Telescope." The article includes a beautiful image of Abell 39 taken with 
the WIYN telescope. Needless to say, my sketch does not compare to the WIYN 
image. In fact, I almost logged this as a non-observation. However, this 
delicate planetary emerged from hiding when I paired a Lumicon OIII filter 
with a 13.8mm (82x) Meade SWA eyepiece.

The best description was offered by an observing companion who uttered, 
"That's [expletive deleted] faint." The circular planetary covers a 3' 
diameter with the east-southeast edge appearing just a tad brighter than the 
remaining perimeter. Abell 39 is bounded to the south by a trio of moderately 
bright stars. A 9th magnitude GSC star stands 15' due south. A similarly 
bright star resides 14' to the southwest. Tenth magnitude GSC 2052:587 lies 
about 13' to the east-southeast. This star has a 12th magnitude partner just 
1'.5 to the southeast.

The night also included non-observations of two Palomar globulars, Pal 3 and 
Pal 4.

Regards,

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