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How deep can Hubble Telescope see?

  1. Oct 24, 2013 #1
    How deep can Hubble Telescope see??

    -I understand that the Hubble telescope can only resolve galaxies at about 13 billion years old, using gravitational lensing. I am curious, is this because the telescope does not have the power to see farther? Or is this because there are no farther galaxies to see because this is too close to the Big Bang? Or, is it perhaps because the redishifts become so great that galaxies disapear at this point? I ask because I am curious to know if the James Webb telescope will actually provide new insight and perhaps even observations of older galaxies. Thanks!

    P.S. - About my last point. At what age does the redshift become so shifted that galaxies no longer are observable (even if this boundary is older than the universe in theory, I am curious to know what it would be)
  2. jcsd
  3. Oct 24, 2013 #2
    I'll have to go look for the piece, but recently I read was that the oldest galaxy we have seen is 30 billion light years away. It is 13.1 billion years old, about 700 million years after the creation of the universe. It was seen by Hubble.

    Link http://www.kbtx.com/home/editorspick/Texas-AM-Researchers-Discover-New-Galaxy-30-Billion-Light-Years-Away-229007511.html [Broken]
    Last edited by a moderator: May 6, 2017
  4. Oct 24, 2013 #3
    Hi, and thanks for the quick reply and link...!! Do you know if the Hubble ST could resolve older galaxies IF the universe were old enough to support them? If the Universe was 16 billion years old, could Hubble resolve 15 billion year old galaxies? I guess I'm trying to asses how powerful HST really is. Thanks!
  5. Oct 24, 2013 #4


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    It is generally believed it took about 500 million years for the first galaxies to form. As noted, we have observed a galaxy that formed when the universe was only 700 million years old. In fact, it is not yet even a full fledged galaxy, but, a proto galaxy. It is visible because it is undergoing a period of star burst activity. The trouble with Hubble is it does not see so well in the far end of the red spectrum and all of these ancient galaxies at the perimeter of the observable universe are heavily redshifted. The James Webb telescope is specially designed for viewing in the red end of the spectrum, and is larger than the Hubble. It is theoretically capable of seeing objects out to about z=16.
  6. Oct 24, 2013 #5
    Ah, I see. Thanks for the great explanation... This is very exciting, it seems the Webb telescope should render some really amazing stuff! Thanks again.
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