Starobserver
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Reged: 06/04/09
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Eta Cassiopeia: yellow / red main sequence dwarfs
#3313064 - 09/03/09 02:19 PM Attachment (69 downloads)
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Sketch and observing report Eta Cassiopeia
Eta Cassiopeia is a strikingly colourful pair of stars. Eta's primary is bright yellow, while its dim companion looks deep orange with a hint of red. This attractive couple lies within an asterism that, using the right magnification, looks like a small dolphin (see my sketch for details). The dolphin asterism consists of 13 stars, oriented southwest northeast, with eta Cassiopeia situated at the tip of the tail fin. Eta Cassiopeia was allready easily split in the 22mm Nagler. After trying all possible magnifications, I liked the view of both the double and the asterism best using the 12mm Nagler T4, giving a magnification of 133x and a field of view of 37'.
For more details on this interesting couple of yellow and red main sequence dwarfs, its discovery, the place on the main sequence etc. please follow this link for the full report.
Edited by Starobserver (09/03/09 02:19 PM)
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frank5817
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Reged: 06/13/06
Loc: Illinois
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Re: Eta Cassiopeia: yellow / red main sequence dwarfs
[Re: Starobserver]
#3313761 - 09/03/09 09:11 PM
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Math,
This is another beautiful pair. Always gets thoses Ooos and Ahas at star parties. What makes this so nice is your great sketch that captures the colors and beauty of the pair.EXCELLENT POST. 
Frank
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Tommy5
Carpal Tunnel
Reged: 03/28/04
Loc: Chicagoland
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Re: Eta Cassiopeia: yellow / red main sequence dwarfs
[Re: frank5817]
#3313854 - 09/03/09 10:12 PM
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Very nice sketch of this colorful pair.
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kraterkid
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Reged: 03/07/05
Loc: Jacumba, California
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Re: Eta Cassiopeia: yellow / red main sequence dwa
[Re: Tommy5]
#3314816 - 09/04/09 12:13 PM
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Superb Math! Lovely color in this unique pairing.
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desertstars
   
Reged: 11/05/03
Loc: Tucson, AZ
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Re: Eta Cassiopeia: yellow / red main sequence dwa
[Re: kraterkid]
#3314839 - 09/04/09 12:25 PM
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A fine rendering of one of my favorite double stars!
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rolandlinda3
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Reged: 01/24/06
Loc: Crozet VA 22932
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Re: Eta Cassiopeia: yellow / red main sequence dwa
[Re: desertstars]
#3314870 - 09/04/09 12:37 PM
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Very nice...a clean sharp sketch.
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Jef De Wit
Carpal Tunnel
Reged: 03/06/09
Loc: Hove, Belgium
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Re: Eta Cassiopeia: yellow / red main sequence dwa
[Re: rolandlinda3]
#3315057 - 09/04/09 02:07 PM
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Math, keep on posting your beautiful sketches. I like them a lot.
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CarlosEH
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Reged: 01/19/05
Loc: Pembroke Pines, Broward County...
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Re: Eta Cassiopeia: yellow / red main sequence dwa
[Re: Jef De Wit]
#3315182 - 09/04/09 03:08 PM
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Math,
An excellent and beautiful observation of Eta Cassiopeia. Thank you for sharing it with us all.
Carlos
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Edwin Quiroga
professor emeritus
Reged: 01/31/08
Loc: Miranda, Venezuela
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Re: Eta Cassiopeia: yellow / red main sequence dwa
[Re: CarlosEH]
#3318549 - 09/06/09 01:32 PM
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Itīs a coincidence that I discovered this pair panning Cassiopeia one week ago with my Pan 35. I could discern a strange form at 17x in this star. When I put my XW10 (60x) I got its real double star nature, with a second component very faint with respect the brighter.
Really nice sketch, Math!
How do you achieve the glossy effect around the brighter stars?
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Starobserver
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Reged: 06/04/09
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Re: Eta Cassiopeia: yellow / red main sequence dwa
[Re: Edwin Quiroga]
#3318652 - 09/06/09 02:48 PM
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Hi Edwin,
I scan my sketches into Photoshop. On separate layers I add the color and the glow of the brighter stars. I get the glow with a brush two or three times as large as the star. The mode I use is the screen mode with the opacity set to 5% and the flow set to 10%. Of course you have to select the right color first.
Clear skies
Math
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Edwin Quiroga
professor emeritus
Reged: 01/31/08
Loc: Miranda, Venezuela
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Re: Eta Cassiopeia: yellow / red main sequence dwa
[Re: Starobserver]
#3318683 - 09/06/09 03:08 PM
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A nice job indeed!
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