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Colored doubles?

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#26 drollere

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Posted 24 September 2012 - 10:32 AM

I might agree with the gold and copper, it's somewhat a personal interpretation. I take it to mean both colors represent various tints between yellow and orange, with gold being more yellow and copper more orange.

the entire issue is whether you want to make a personal or consensus judgment. if you want to make a personal judgment, then there is no reason not to replace "pale lilac with a topaz tint" with "the color of my favorite socks." who cares whether anyone else can interpret that? to you it makes perfect sense.

if you want to make a consensus judgment, in other words a scientific judgment, then long experience in a variety of disciplines shows that you get there by using a standard rather than personal procedure. "copper" is a dull orange, and "gold" is a pale orange yellow.

It is possibly explained if you consider that Females have a different proportion of Cones to Rods then men, as well as Age deterioration of our Cornea.

this is a misconception about color as a sensation: the obvious example is that our lenses yellow with age, but we notice no color change across the life span. our personal color experience gets remapped onto the increasingly filtered light, and color experience stays the same. in the same way we adjust effortlessly when the illuminant (color of ambient illumination) changes. color is always an interpretation of retinal data.

the counterargument is that, if we individually all have different color vision capabilities, then how can we all agree on describing a colored object? because color language is just a form of consensus interpretation, which individuals learn to map so that their descriptions match those of other people. and the surest way to do that is to restrict the color descriptions to a limited number of categorial terms used in a limited number of combinations. color description is always an interpretation of how to use color language.

I must say that Sissy's "unique" color descriptions have motivated me on more than one night to hunt down an otherwise obscure (i.e., non-famous) double just to see what "pale topaz with a lilac tint" was all about.

of course; no question. but speech with a motivating intent is rhetoric, and speech that motivates a purchase outcome is marketing. haas's descriptions implicitly borrow from the marketing lexicon in wallpaints, foods, cosmetics, fashion and decor. they are pretty, poetic, enthusiastic, evocative, suggestive. they made you run out and look. i myself refer to 61 cygni as "coppery" because i have an affection for the pair. by all means, let us share the joy of color, and encourage enthusiasm in others.

there is a significant difference between speech that intends to convey or arouse feeling, and speech that intends to record sensory data. i commended david's language because it sets a basic framework in which the OP, who has an issue with star color, can navigate his own exploration reliably.

analytic color description respects the fact that the distinction between "yellow" and "no color" is on a different level from the distinction between "straw" and "maize". it ensures that the distinction can be affirmed as a fact rather than debated as a personal difference in sophistication or taste, and does not imply a precision that is inappropriate for delicately and elusively colored star images.

#27 Tom and Beth

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Posted 24 September 2012 - 12:21 PM

Can you actually see the colors in colored doubles? Which doubles actually show their colors through the eyepiece? Thanks.
Jim


Yesterday someone posted this link with a very convenient list of interestingly colored double stars. I have immediately bookmarked that link, but have evidently forgotten to who the credit is due.....

F.


Over the last few nights I've enjoyed observing many pairs on this list, several of them new to me. Thanks

EDIT: One of the stars new to me (and actually not sure how I've missed it) is Almaak, AKA Gamma AND. The Blue Component is also a double star, although you'll need quite a telescope to split it with the 0.4 Arc Second separation.

#28 edwinh

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Posted 25 September 2012 - 11:58 PM

Yes, me too. I have not been excited by double-star observing so far other than the obvious Albireo, but after just browsing this forum and this particular thread, decided to give it a try again.

Knocked out all the cas/peresus/aries/and. ones just the last hour or two. Nice with the color contrasts. Consider me converted. Thanks again to whomever posted the link, and the list up above in this thread.

#29 fvandrog

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Posted 26 September 2012 - 03:39 AM

if you want to make a consensus judgment, in other words a scientific judgment, then long experience in a variety of disciplines shows that you get there by using a standard rather than personal procedure. "copper" is a dull orange, and "gold" is a pale orange yellow.


Even those color descriptions don't count as objective scientific statements. In most papers spectra and wavelengths are relatively carefully described. Of course those can be 'translated' back to colors, but since color, but since seeing colors is rather subjective and differences between people are large its easy to get misunderstanding that way.

I guess everybody know someone that insists a clearly green shirt is blue -- or the other way around. Evidently, they are mistaken ;) , but these issues makes attributing colors to stars tricky.

#30 David Knisely

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Posted 26 September 2012 - 06:07 PM

drollere wrote:

one merit worth emulating in knisely's list is his analytic color language. it consists of basic hue terms (red, orange, yellow, green, blue, violet, white), plus modifying blends (blue white, yellow orange, etc.), plus the tint designators "ish" (yellowish orange), plus the saturation designator "pale". star colors are rarely strongly saturated, excepting perhaps carbon stars, but "intense" is a high saturation term to keep handy.


Well, I have yet to see any star (double or otherwise) that is a "violet" color. What I see (from hottest to coolest and the approximate spectral class) are a pale blue (O and early B spectral types), bluish-white (late B and A spectral types), white (mostly F class), off-white (cream, late F to early G class), yellowish-white (mid G class and giants), yellow (mostly K-class), orange (late K-class to early M-class), and reddish-orange (mid to late M-class). Carbon stars appear to me as a deep reddish-orange, although they tend to be a little redder when in the faint phase of their light curves. Otherwise, I don't really see the other somewhat wilder "colors" that were commonly reported by some of the historic visual double star observers. Clear skies to you.

#31 azure1961p

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Posted 26 September 2012 - 08:40 PM

drollere wrote:

one merit worth emulating in knisely's list is his analytic color language. it consists of basic hue terms (red, orange, yellow, green, blue, violet, white), plus modifying blends (blue white, yellow orange, etc.), plus the tint designators "ish" (yellowish orange), plus the saturation designator "pale". star colors are rarely strongly saturated, excepting perhaps carbon stars, but "intense" is a high saturation term to keep handy.


Well, I have yet to see any star (double or otherwise) that is a "violet" color. What I see (from hottest to coolest and the approximate spectral class) are a pale blue (O and early B spectral types), bluish-white (late B and A spectral types), white (mostly F class), off-white (cream, late F to early G class), yellowish-white (mid G class and giants), yellow (mostly K-class), orange (late K-class to early M-class), and reddish-orange (mid to late M-class). Carbon stars appear to me as a deep reddish-orange, although they tend to be a little redder when in the faint phase of their light curves. Otherwise, I don't really see the other somewhat wilder "colors" that were commonly reported by some of the historic visual double star observers. Clear skies to you.


I actually have seen lavender stars. They arent REALLY lavender of course. It was one of MacRoberts star hop articles way back, I belive in Lyra and there was some yellow star ... maybe third mag or more and the star near it was noted as lavender. I laughed when I read it but this dimmer star [magnitude 9 maybe] distinctly appeared to hayve a grey lavender tinge. Total contrast effect thrown off by the bright yellow star near it. Would I have seen it as lavender without MacRoberts suggestion - I doubt it. But after that point the lavender/yellow contrast effect has reared its head from time to time. Ive still NEVER seen a green star.

Pete

#32 Perigny270

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Posted 20 October 2012 - 07:42 PM

I enjoy everybody's descriptions. This has been fun reading. I will go look for more of the ones with the interesting colours - for me it is the difference between them that stands out. But then, some of those intense blue pairs are special...

#33 Hal9000

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Posted 07 November 2012 - 09:24 PM

Yesterday someone posted this link with a very convenient list of interestingly colored double stars. I have immediately bookmarked that link, but have evidently forgotten to who the credit is due.....

F.



Great link F...Al






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