frank5817
Post Laureate
Reged: 06/13/06
Posts: 3050
Loc: Illinois
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At a distance of 9,300 light years (2850 parsecs) this youthful open cluster is about the same age as the Perseus Double Cluster – eight million years old. NGC 457 in Cassiopeiae is composed of nearly 100 stars brighter than magnitude 13 and many fainter members. The cluster has several names including the Owl cluster, the E.T. cluster, the Phi Cas. cluster and others. The two brightest stars here, Phi Cas. and HD7902 may not actually be members of this open cluster but rather foreground stars. These two stars form the bright eyes of the owl. Phi Cas. is a magnitude 5 yellow star and HD 7902 is a magnitude 7 bluish star. If the brighter member is a cluster star at 9,000 light years it would have a luminosity of 275,000 suns. The integrated visual magnitude of this cluster is about 6.4 and it is 16’ across. This object was discovered by William Herschel in 1787. It can easily be found 2° south-southwest of delta Cas. (R. A. 1h. 22’, Dec. +58° 2’).
Sketching
Date and Time: 8-11-2008, 5:20-6:40 UT
Scope: 10” f/5.7 Dobsonian. 13mm eyepiece 111x
8”x11” white recycled sketching paper, 4B soft charcoal pencil, HB hard charcoal pencil, blending stump, scanned and inverted, some star magnitude adjustment made at the time of scanning.
Seeing: Pickering 5/10
Transparency: Average 3/5
Nelm: 4.2
Frank McCabe 
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CarlosEH
Post Laureate
Reged: 01/19/05
Posts: 3126
Loc: Pembroke Pines, Broward County...
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Frank,
An excellent observation of the Owl Cluster (NGC 457) in Cassiopeia. You have captured the glow of the cluster nicely. Thank you for sharing it with us all.
Links;
http://www.hawastsoc.org/deepsky/cas/index.html
http://www.robgendlerastropics.com/NGC457.html
Carlos
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frank5817
Post Laureate
Reged: 06/13/06
Posts: 3050
Loc: Illinois
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Carlos,
Thank you for your kind words and adding the links about NGC 457.  The photo in the second link is stunning. 
Frank
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xfile101
professor emeritus
Reged: 12/08/07
Posts: 739
Loc: Ocean Gate, NJ
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Nice one Frank. I have yet to grab a view at this one but I will be sure to see it now, thanks to your sketch! Real nice 
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Orion XT8I
Celestron 114EQ Firstscope
Meade 70mm
Astroscan
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frank5817
Post Laureate
Reged: 06/13/06
Posts: 3050
Loc: Illinois
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Frank,
Thank you. I think you will like this open cluster.
Frank 5817
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GlennLeDrew
professor emeritus
Reged: 06/18/08
Posts: 633
Loc: Ottawa, Ontario, Canada
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Frank,
That is indeed a nice drawing, and it accords well with my own visual impressions as seen in medium to large scopes.
By the way, most sources I've seen do accept phi Cas as a member, as well as HD7902. Phi is one of the more luminous stars known, and its HD type is F0 Ia, meaning it's a yellowish luminous supergiant. HD7902 is a B6 Ib, or a blue, less luminous supergiant.
The presence of such bright members is a good indicator of youth.
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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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frank5817
Post Laureate
Reged: 06/13/06
Posts: 3050
Loc: Illinois
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Glenn,
Thank you for the comments about my sketch. This open cluster is a fine one and I have found it to be most interesting. In my searches over the years I find an equal number of arguments for and against Phi Cas. and its companions being members of this cluster. The late Robert Burnham Jr. in his work “Burnham’s Celestial Handbook”, page 530 and written in the late 1960’s puts Phi Cas as a cluster member. In 2002 Steven J. O’Meara published in his book “The Caldwell Objects” that the jury is still out on Phi Cas. being a member. In late 2007, Jim Kaler an emeritus professor of Astronomy at the University of Illinois outlines several problems with Phi Cas being a cluster member www.astro.uiuc.edu/~kaler/sow/sowlist.html A reliable parallax measurement would be helpful but the error at a few thousand light years is very large as I’m sure you know.
Now you may know a more recent study that confirms membership but I do not know of it. A definitive answer one way or another would be nice.
Frank
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dlapoint
sage
Reged: 08/18/03
Posts: 452
Loc: Moncton NB Canada
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Nice sketch! I sketched it with a 5" refractor under city lights. I seen fewer stars but the basic shape and star brightness matches with mine. I would agree that this would give a real good picture of the view in a bigger scope. Nice work!
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Antares 127 F6.5
Skywatcher Pro ED100
Orion 72mm Eon
Orion XT8
C4.5
Naglers 16mm T5, 9mm T6
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Tommy5
Pooh-Bah
Reged: 03/28/04
Posts: 1394
Loc: Chicagoland
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great sketch of one of my favorite clusters, monday night i brought the 6" achro with me to dark skies in michigan,M-33 was easy in binoculars! best night of observing in my life! i will post a report in the dso observing forum, anyway great sketch.again.
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frank5817
Post Laureate
Reged: 06/13/06
Posts: 3050
Loc: Illinois
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Tommy5,
This may be the best open cluster in Cassiopeiae. Thank you for your compliments. Your trip to Michigan sounds like a memorable event. Can't wait to read your report in the DSO forum.
Frank
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frank5817
Post Laureate
Reged: 06/13/06
Posts: 3050
Loc: Illinois
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Diapoint,
Thank you. City lights make for tough observing. I would think you five inch scope would show the cluster very nicely. Like some open clusters this one has a good many bright telescope stars.
Frank
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rodelaet
Carpal Tunnel
Reged: 04/28/06
Posts: 2662
Loc: 50°56' N - 4°58' E (Belgium)
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Frank,
I'm happy for you that you got some quality time in deep-sky. And you choose an excellent target.
Wonderful sketch of one of my favorite clusters. 
Keep them coming, those sketches, Frank. 
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Rony
My Astronomy Sketches
My Binocular Sketches
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frank5817
Post Laureate
Reged: 06/13/06
Posts: 3050
Loc: Illinois
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Rony,
Thank you My home location limits my DSO a great deal but it does not stop me entirely.
By this time in the year your nights must be getting a little longer and darker. I have really been enjoying your binocular sketches tremendously. Please keep going. 
Frank
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Chippingdale
member
Reged: 10/13/05
Posts: 11
Loc: Hertfordshire UK
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Dear Frank,
I love that cluster it looks great in any instrument. You have prompted me to put it top of my list for sketching.
Thanks, Dale
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frank5817
Post Laureate
Reged: 06/13/06
Posts: 3050
Loc: Illinois
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Dale,
If you do decide to sketch it, do please post your sketch here so everyone can see what a fine sketch artist you are.
As fall approaches maybe you will also get some nice clear nights.
Frank
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mickmrn1
member
Reged: 05/18/08
Posts: 25
Loc: Mesa, Arizona
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Frank,
Very impressive sketch. I will take a look at this soon!
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Michelle D.
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frank5817
Post Laureate
Reged: 06/13/06
Posts: 3050
Loc: Illinois
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Michelle,
This is an easy one to locate and looks great in any scope.
Thank you.
Frank
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