Author Topic: extra credit  (Read 3130 times)

vvpeyton

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extra credit
« on: December 06, 2009, 10:41:18 pm »
If the color on a galaxy is more faded and not as vivid, does that mean there is less gas or does it have anything to do with the age of the galaxy?
« Last Edit: December 07, 2009, 01:58:20 am by vvpeyton »

taylorfan411

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Re: galaxy question
« Reply #1 on: December 06, 2009, 10:59:00 pm »
Dear vvpeyton,
 I personally think that if the color of a galaxy is more faded, then that reflects on its age. I also think that the more faded a galaxies colors are, the longer they have been in outer space.
« Last Edit: December 06, 2009, 11:02:56 pm by taylorfan411 »

Haley Lyman

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Re: galaxy question
« Reply #2 on: December 07, 2009, 12:34:18 am »
i think that if the color of the galaxy determines how old the galaxy is. The brighter, clearer, more vivid ones are most likely younger than the dull ones.

CarlaS

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Re: galaxy question
« Reply #3 on: December 07, 2009, 01:34:59 am »
Dear vvpeyton,
I think that some galaxies are more faded than others because they have less gas. I also think that they might look more faded than other galaxies because of the way the picture was taken. The picture could have been blurred so the galaxy might look faded.
CarlaS

Margaret Lewis

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Re: extra credit
« Reply #4 on: December 07, 2009, 02:12:02 am »
I think it has to do with fading by expanding and old age.

meggie w

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Re: extra credit
« Reply #5 on: December 07, 2009, 04:04:41 pm »
I think that if the color is more faded the galaxy is older because when galaxies are first born their color is brighter and clearer but as they grow older and are getting closer to dyeing they begin to fade in appearance until eventually they disappear and die.

zookeeperChris

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Re: extra credit
« Reply #6 on: December 14, 2009, 10:12:02 pm »
I'm not too sure what you mean by faded, but the colour of a galaxy tells us about its recent star formation. Blue stars are large, bright and (relatively) short-lived so whenever you see them you know that galaxy has formed stars in the last few hundred million years or so. Galaxies that don't have blue stars are populated by older stars.

Beware, though! Because the blue stars are bright you don't need that many of them to distract you from what's going on underneath. It's quite common to have a galaxy with an old population of stars appear blue because of recent star formation that's created, say, 5% of its stars. These galaxies are actually quite interesting - finding them was one of the original goals of Galaxy Zoo - but they do create a headache if you're trying to draw conclusions about age from colour.

Hope that helps - let me know if not.

Chris

starry nite

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Re: extra credit
« Reply #7 on: December 15, 2009, 01:58:20 pm »
The color and brightness of objects on SDSS/SkyServer are also sometimes altered by local sources such as stars or the alignment of the plates when the images were taken (amongst other reasons).
« Last Edit: December 15, 2009, 02:04:26 pm by starry nite »
Good news everyone!