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PhilH
sage
Reged: 01/27/05
Posts: 232
Loc: Long Island, NY
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Not exactly a barn-burner, but open cluster NGC 188 in Cepheus is always a fun test object to try and hunt down. Here's my attempt at sketching the view through my 4-inch refractor.
NGC 188 lies only 4° from the North Celestial Pole, keeping it above our northern horizon throughout the year. That's a plus, but also a minus. Its location in a sparse portion of the sky discourages many an amateur from even trying to spot it, especially if using an equatorially mounted instrument. Trying to aim at something so close to the celestial pole, where the polar-aligned telescope has to be twisted around the mount's right ascension axis at wild angles, is an exercise that only a contortionist can appreciate.
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Phil Harrington
"Binocular Universe" Columnist, Astronomy magazine
Author: Star Ware || Star Watch || Touring the Universe through Binoculars || et al...
http://www.philharrington.net
http://www.observingsites.com
"Two eyes are better than one!"
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frank5817
Post Laureate
Reged: 06/13/06
Posts: 3005
Loc: Illinois
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Phil,
This is a fine sketch of a good open cluster.  I like this drawing very much. 
Frank 
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mike bacanin
sage
Reged: 03/19/07
Posts: 342
Loc: united kingdom
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Hi Phil,
a lovely sketch!
regards
Mike
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CarlosEH
Post Laureate
Reged: 01/19/05
Posts: 3082
Loc: Pembroke Pines, Broward County...
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Phil,
An excellent observation of an interesting open cluster in Cepheus. Thank you for sharing it with us all.
Carlos
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rodelaet
Carpal Tunnel
Reged: 04/28/06
Posts: 2632
Loc: 50°56' N - 4°58' E (Belgium)
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Nice sketch, Phil.
I ran into this object while attempting to observe the Caldwell list. NGC 188 is the first object in that list. It's not an easy object. I could not see much of it under mag 5.5 skies with a 4" scope.
Makes me wonder what your nelm was, Phil?
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Rony
My Astronomy Sketches
My Binocular Sketches
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GlennLeDrew
professor emeritus
Reged: 06/18/08
Posts: 574
Loc: Ottawa, Ontario, Canada
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When the NELM is >= 6.5, I can spot NGC188 in 7x35 binos. When the NELM is a brighter 6.3, it takes something closer to 10x50s. But either way, these detections are a testament to the power of two-eyed viewing, which yields a 41% gain in signal-to-noise, or 0.37 magnitude.
Phil,
Do you feel that you were seeing any of the brighter giants in this cluster with the 4"? I ask because in your sketch there seems to be a concentration in the fainter star-dots superimposed upon the glow of the cluster's unresolved members.
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Home-made 11X50 right angle bino, 8.1 deg. FOV
Modified 26X100 bino, 3.5 deg. FOV
Mediocre minds discuss people. Good minds discuss events. Great minds discuss ideas.
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WadeVC
Carpal Tunnel
Reged: 12/02/05
Posts: 2779
Loc: Lodi, California,
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Phil,
Nice sketch of a beautiful OC. I find many of the OC's to be both a challenge and fun to sketch; they can keep you at the EP for extended times, that is for sure.
Nice! 
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Orion XTi10 f/4.7
Orion XTi8 f/5.9
Meade NGC 70mm f/10
Orion UltraView 10x50 Wide-Angle Binoculars
My Sketch Gallery
My Astronomy Blog
A wise man can see more from the bottom of a well than a fool can from a mountain top.
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PhilH
sage
Reged: 01/27/05
Posts: 232
Loc: Long Island, NY
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Quote:
I could not see much of it under mag 5.5 skies with a 4" scope. Makes me wonder what your nelm was, Phil?
Thanks everyone for your kind words. In this case, Rony, the skies were about mag 6, maybe 6.1. I was up at a small astronomy convention in western Massachusetts at the time. The northern sky is the darkest, which helped again with seeing the object. All I really saw was the the very slightest hint of a glow surrounding a few faint stars. Not exactly a showpiece object.
Including NGC 188 as the first entry makes me question the whole premise behind the so-called Caldwell list. But then, I won't open that can of worms right now! 
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Phil Harrington
"Binocular Universe" Columnist, Astronomy magazine
Author: Star Ware || Star Watch || Touring the Universe through Binoculars || et al...
http://www.philharrington.net
http://www.observingsites.com
"Two eyes are better than one!"
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PhilH
sage
Reged: 01/27/05
Posts: 232
Loc: Long Island, NY
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Quote:
Do you feel that you were seeing any of the brighter giants in this cluster with the 4"? I ask because in your sketch there seems to be a concentration in the fainter star-dots superimposed upon the glow of the cluster's unresolved members.
Good question, Glenn. I haven't bothered to check exactly which cluster stars I was seeing, but since NGC 188 is one of the oldest clusters known, I suspect I probably saw a few of them. As you probably know, the hottest main sequence star in the group is spectral class F2, with many others rated as spectral classes G and K. No chance of seeing at subtle coloring in such a small aperture, but it would be interesting to study the group with a large aperture, to see if any indication comes through.
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Phil Harrington
"Binocular Universe" Columnist, Astronomy magazine
Author: Star Ware || Star Watch || Touring the Universe through Binoculars || et al...
http://www.philharrington.net
http://www.observingsites.com
"Two eyes are better than one!"
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