The new ultra-powerful Hubble Space Telescope found yesterday a galaxy whose light traveled more than 13 billion light-years to get to earth, making it the oldest astronomical object ever discovered.
A title previously held by a gamma-ray burst, UDFy-38135539, formed within 600 million years of the universe’s creation, 14 billion years ago.
“I don’t think this is the limit, perhaps not even that close to it,”
Said lead researcher Matthew Lehnert, with France’s Observatoire de Paris,
“UDFy-38135539 was already a challenge and perhaps we won’t be able to do much better than it for a while yet.”
The term “Redshift” refers to what happens when light coming from an object is shifted to appear redder. The universe today is redshift 0. Redshift 1 refers to when the universe was half its present age.
“Redshift 8.6 is likely to be about as high as we can reach with the current generation of telescopes,”
Said astrophysicist Michele Trenti of the University of Colorado in Boulder.
“With the Hubble Space Telescope it might be possible to find some galaxies up to redshift 10, but these objects are expected to be very rare and extremely faint.”
Verification of a galaxy within 600 million light-years of the Big Bang is exceptionally interesting to scientists because its during this time that radiation from the first objects in the universe stripped off electrons from hydrogen atoms created during the Big Bang.
“It’s quite amazing to me that humble, small galaxies — the ones that likely existed at this high redshifts, early in the history of the universe — could literally change its overall state,”
Said Lehnert,
“It raises the question what are these other sources and are they like UDFy-38135539 or not? We know from the (Hubble Ultra Deep Field) images that whatever they are, they are not detected in those images. We need more data and much deeper data.”