The earliest known astronomical object is a galaxy appearing about 600 million years after the universe formed.
Homing in on an object found during the Hubble Space Telescope’s long, deep stare into the distant past, astronomers have fished out a galaxy whose light has traveled more than 13 billion light-years to get here, making it the oldest astronomical object found so far.
The universe’s most senior citizen is called UDFy-38135539, but scientists suspect its title as record-holder — previously held by a gamma-ray burst — will not last.
“I don’t think this is the limit, perhaps not even that close to it,” lead researcher Matthew Lehnert, with France’s Observatoire de Paris, told Discovery News.
Measurements taken of UDFy-38135539 by Lehnert and colleagues confirm it formed within 600 million years of the universe’s creation. Theoretical models and computer simulations suggest that the first galaxies could have formed as early as 200 million years after the Big Bang event.
Lehnert says it will be increasingly more difficult to find these objects, since they would be extremely faint and have much fewer stars and gas to make their presence known.
“UDFy-38135539 was already a challenge and perhaps we won’t be able to do much better than it for a while yet,” Lehnert said, adding that it took about four years of work to make the jump from the 2006 detection of the previously known most distant galaxy, which existed about 750 million years after the Big Bang (a distance referred to in scientific parlance as a redshift of 6.96) to confirmation of UDFy-38135539 at a redshift of 8.6.
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