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Eta Cassiopeia: yellow / red main sequence dwarfs

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#1 Starobserver

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Posted 03 September 2009 - 01:19 PM

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.

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#2 frank5817

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Posted 03 September 2009 - 08:11 PM

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. :bow: :cool: :rainbow:

Frank :)

#3 Tommy5

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Posted 03 September 2009 - 09:12 PM

Very nice sketch of this colorful pair.

#4 kraterkid

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Posted 04 September 2009 - 11:13 AM

Superb Math! Lovely color in this unique pairing. :bow:

#5 desertstars

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Posted 04 September 2009 - 11:25 AM

A fine rendering of one of my favorite double stars!

#6 rolandlinda3

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Posted 04 September 2009 - 11:37 AM

Very nice...a clean sharp sketch.

#7 Jef De Wit

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Posted 04 September 2009 - 01:07 PM

Math, keep on posting your beautiful sketches. I like them a lot.

#8 CarlosEH

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Posted 04 September 2009 - 02:08 PM

Math,

An excellent and beautiful observation of Eta Cassiopeia. Thank you for sharing it with us all.

Carlos

#9 Edwin Quiroga

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Posted 06 September 2009 - 12:32 PM

It´s 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?

#10 Starobserver

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Posted 06 September 2009 - 01:48 PM

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

#11 Edwin Quiroga

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Posted 06 September 2009 - 02:08 PM

A nice job indeed! :waytogo:






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