Bonus: Double Stars at Zenith -A neck breaker!- May 2008

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BobSikes
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Bonus: Double Stars at Zenith -A neck breaker!- May 2008

Unread post by BobSikes »

Start with Cor Caroli (the heart of Charles I star) in Canes Venatici and visit the constellations a zenith this month (Canes Venatici, Corona borealis, Ursa Major, Coma Berenices and Boötes and see how many of double stars you can find. Please give each find a nice double star description (relative magnitudes, colors, separation and position angles). The viewing is best at zenith, but you may need to visit a chiropractor for that neck if you do this standing up.

Prize goes to the most/best postings.

Note: I'll post some lists for binocular and telescope doubles in these constellations when I can, but don't let that stop you. Let's see what you can find!
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Galactus
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Unread post by Galactus »

I still swear that I saw a lot of color differences between many of the doubles I observed with Bob M and Bob S on Saturday night. I think my color receptors may be a tad more sensitive as even when "double checking" pun intended, I saw the colors in the same ways in differing telescopes.

Cor Corolli definitely was a blue fringed white with a Gold/orange companion.

The Double Double was blue/pink in the first split through my binos. But in Bob M's refractor there was no color difference between the four when splitting the Double Double further. Thanks for all the tips on observing double stars, guys it was a lot of fun!
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Rotorhead
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Unread post by Rotorhead »

Very serendipitous that you should pick double stars this month, Bob, as I had a list of 15 doubles in my pocket for observing after the meeting. For this purpose, I had packed my 6" Celestron, since I find it does a better job of splitting close doubles than the bigger dob. Probably has more to do with f/ratio and focus than anything. I know the refractor is right on the money with collimation, too.

After the meeting I mentioned to the crowd outside that I would be trying to split some doubles, and I had about five adults and three of the youngsters follow me to the field.

We started with Cor Caroli, which is easy. As anticipated, I see only white/white on this one (maybe a tint of blue on the secondary) but the youngsters saw the secondary as reddish or purple. Sissy Haas in her book 'Double Stars for Small Telescopes' describes them as white and blue/green. She also includes comments about other observers, so that color differences may also be included. George's reported colors do not surprise me, as very many people have widely divergent night color perception.

We then moved to Algeiba (gamma Leonis) to split two orange stars of unequal size and a much closer separation than Cor Caroli. Some youngsters saw a shade of green in the secondary (verified by some experts in the book).

We then began my list, and ran (not in this order) the following (mostly at 140x unless noted):

Kappa Herculis: Yellow primary/smaller purplish secondary with a nice triangle of stars to the NE. Probably an optical double.
Alpha Herc: Very close pair, with a large gold primary and bright blue secondary (like a close Albireo) and two field stars. Very pretty! True double, with a 500 year period.
Rho Herc: Another yellow primary/blue secondary, this time with both stars being much smaller. Again, two background stars in the field. Probably a four-star complex, and probably a true binary, at least for the two stars we see, but with a very long period.
95 Herc: A very pretty pair of medium sized gold stars of nearly the same size in a nice field of white stars. True binary.
Delta Herc: A large yellow primary with a tiny blue secondary (about the same proportions as Polaris) with a modest separation surrounded by a triangle of white background stars and a few others.

We then shifted to Lyra for three more doubles, reported at the Lyra challenge thread.

While these were outside the constellations of this challenge, I'm reporting them to try to whet some interest. Thanks, Bob, for coming up with this month's challenge. I want to get some more fava beans, so I'll keep looking up! :D
Last edited by Rotorhead on Tue May 13, 2008 3:43 pm, edited 1 time in total.
Bob M
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BobSikes
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Unread post by BobSikes »

At this rate, you going to have a pot o' beans by month's end. Nice!

I'm with you on colors, but I think aging cones (the cells that detect color in the eye) seems a likely factor. When I first looks at Cor Caroli, I just saw a nice, whitish pair. George saw a rainbow. I looked more carefully and saw the marked difference in color of the secondary, grey blue vs glaring white with a slight touch of yellow. Sigh.

It's nice to hear that the youngsters were enjoying the colorful doubles, glad you brought your scope!

BobS
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Rotorhead
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Unread post by Rotorhead »

Oops, Struve 525 is in Lyra. :oops: Sorry I moved it, I'll put it back where it belongs...
Bob M
15" f5 Starsplitter Dob/80mm Finder
5" Explore Scientific triplet APO on a Vixen Sphinx GEM
________
"He numbers all the stars, and calls each one by name." Ps 147:4
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Galactus
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Unread post by Galactus »

Interesting. While my aging--at 54--eyes have a bit of difficulty with dimmer objects or seeing the first star in a still blue sky, I do see differences in color in bright stars, especially doubles since they are both bright and close to each other for comparison. Most of the time I see white, however, I seem to see more colors than some observing with me. (so much so that I am often accused of imagining the color) This is all very subjective. It is fun to compare notes...
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Mark G
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Unread post by Mark G »

gnhuftalen wrote:Interesting. I seem to see more colors than some observing with me. (so much so that I am often accused of imagining the color) This is all very subjective. It is fun to compare notes...
A bit off topic but it could be relavent...

Can you say "THC bubble" George :P :lol: Just kidding. Everyones eyes are different and the rod's & cones of the human eye can vary from person to person. Genetics, age, as does diet, and how you "learned" to see all factor in... So subjective is just the word to use George.

For what it's worth my "good eye" as Matt calls it has the largest macular my opthalamogist his ever seen. I've a digital image of it somewhere here, I should post it for giggles. ....rummage .... rifle.... rummage... a here it is.... :shock: I found it :!:

Image

The Macular is the usually a darker colored area left of the optic nerve (where the blood vessels originate from). The small ring is the center of my macular (again left of the optic nerve) You can see that it spreads out over much of the back area of my retina in the image?

A normal eye for coparison: taken from Stlukeseye.com
Image

A refesher for myself :lol: again from stlukeseye.com

Retina
The retina is a multi-layered sensory tissue that lines the back of the eye. It contains millions of photoreceptors that capture light rays and convert them into electrical impulses. These impulses travel along the optic nerve to the brain where they are turned into images.

There are two types of photoreceptors in the retina: rods and cones. The retina contains approximately 6 million cones. The cones are contained in the macula, the portion of the retina responsible for central vision. They are most densely packed within the fovea, the very center portion of the macula. Cones function best in bright light and allow us to appreciate color.

There are approximately 125 million rods. They are spread throughout the peripheral retina and function best in dim lighting. The rods are responsible for peripheral and night vision.

This photograph shows a normal retina with blood vessels that branch from the optic nerve, cascading toward the macula
.
Last edited by Mark G on Tue May 13, 2008 7:55 pm, edited 1 time in total.
Clear skies,

Mark

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Rotorhead
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Unread post by Rotorhead »

Wow, for a second there I thought somebody had gotten a great close-up image of Antares with a very close companion...
Bob M
15" f5 Starsplitter Dob/80mm Finder
5" Explore Scientific triplet APO on a Vixen Sphinx GEM
________
"He numbers all the stars, and calls each one by name." Ps 147:4
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Mark G
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Unread post by Mark G »

Rotorhead wrote:Wow, for a second there I thought somebody had gotten a great close-up image of Antares with a very close companion...
I did say a bit off topic... :lol: But I tied it in with the color of stars comment.
Clear skies,

Mark

iOptron CEM25P w/ Tri-pier
CGEM DX
LXD750 w/ CDS #1697
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Antares 4" f/15 "Vixen Spec" long focus refractor
Orion 4" f/7 ED refractor
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and so much more
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Unread post by Bruce D »

I cracked an egg open one time and the yolk looked like that. Does that mean anything?
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