Scientists have confirmed the discovery of the oldest
and most distant supernova ever photographed.
The faint remnants of the exploded star, more than 10
billion light-years distant, offer new clues to the formation of the early
universe.
When a massive star explodes, it’s called a supernova
and is one of the most violent events in the universe. The bright, distinctive
remnants of these explosions can be seen throughout the cosmos, and they
provide valuable reference points for astronomers trying to measure the
expansion of the universe.
Scientists know the rate of that expansion
is accelerating, but they don’t know why, says David Rubin, a member of the Supernova
Cosmology Project at the University of California, Berkeley.
“We are currently working to make better and better
measurements at greater and greater distance to pin down the source of the
acceleration and determine its properties,” he said.
Ruben is studying type IA supernovae because they have
uniform brightness, which means, he says, “If we observe a supernova and we
observe its apparent brightness here on Earth, we can learn its distance. We
can make a plot of the distance versus the expansion and try to distinguish
various theories of acceleration.”
Using the Earth-orbiting Hubble Space Telescope, the
astronomers first spotted the distant supernova in a deep-space survey.
Its light was so dim it was nearly invisible, and researchers had to wait
five years for a more advanced camera to be installed aboard Hubble to confirm
that the tiny point of light really was a supernova.
Cosmic
images from the American Astronomical Society meeting in Long Beach, California:
Sources :
http://www.voanews.com/content/ten-billion-year-old-supernova-oldest-ever-identified/1581709.html
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