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Thread: Do we actually know what colour objects in space are?

  1. #1 Do we actually know what colour objects in space are? 
    Forum Freshman Incoming Dessert's Avatar
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    Everyone must have seen some of the breathtaking images telescopes produce, of far distant galaxies and stars and things of a similar nature. And one of the things that make them look so good is the colour, with vivid reds and greens and blues. But when you look at the nature of telescope that took the pictures in question (X-ray, radio, etc) you see that they're not actually working in the visibly spectrum, so are the colours in the pictures the actual colour of the objects?


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    New Member BUGZ's Avatar
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    I've recently read book about this. The human eye adjust itself to colors. For example, if you are in tropical forest and you have a sheet of paper /usually white, but there green - the light is filtered by plants/, you'll see it white, not green, as it is, because your brain manipulates colors. Telescopes make the same thing with the space objects' color. So, if you could see in that spectrum, you would see exactly what is in the picture. *

    Correct me if I'm wrong.

    * Is there such construction in English - could + would for imaginary situation? I'm can't speak very well English, excuse me.


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  4. #3 Re: Do we actually know what colour objects in space are? 
    . DrRocket's Avatar
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    Quote Originally Posted by Incoming Dessert
    Everyone must have seen some of the breathtaking images telescopes produce, of far distant galaxies and stars and things of a similar nature. And one of the things that make them look so good is the colour, with vivid reds and greens and blues. But when you look at the nature of telescope that took the pictures in question (X-ray, radio, etc) you see that they're not actually working in the visibly spectrum, so are the colours in the pictures the actual colour of the objects?
    If you read the captions that go along with some of those images you will see that they are in "false color". Since you cannot see infrared or x-rays it is necessary for the signals taken by the telescopes to be processed and images rendered in a form that you can see.

    That is not anything special. In essence that is what is done with ordinary medical x-rays. The signal is rendered there as a black and white iimage the intensity of which is related to x-ray absorption, which is essentially density. It is also done with sonograms, which interpret sound signals in the form of an image.
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    actually .. stars do giv off the colours we see .. its because of the elements that are currently in nuclear fusion giving off those colours
    im just a bored student trying to get his SRP done (:
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    When you look in a smaller telescope, most galaxies appear yellow-gray.
    It's a limitation of the human eye.
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  7. #6  
    . DrRocket's Avatar
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    Quote Originally Posted by skivvies
    actually .. stars do giv off the colours we see .. its because of the elements that are currently in nuclear fusion giving off those colours
    And colors that we don't see. But what is relevant is the colors that are detected by a particular telescope and how the image is processed before it is released as the "pictures" that you see (on internet sights for instance).

    Also the nuclear fusion provides energy, but the reason that stars shine is becaue they are hot. The temperature is the primary factor in determing the spectrum which is generally a black-body spectrum.
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