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http://news.bbc.co.uk/2/hi/science/nature/4237800.stm
Most distant cosmic blast sighted
"Astronomers have witnessed the most distant cosmic explosion on record: a gamma-ray burst that has come from the edge of the visible Universe.
Gamma-ray bursts are intense flares of high-energy radiation that appear without warning from across the cosmos.
They can release as much energy in a few minutes as our Sun will emit in its expected 10-billion-year lifetime.
The blast was observed by the Swift space telescope and by a number of ground-based observatories.
The latest, record gamma-ray burst was detected on 4 September, 2005, and lasted about three minutes. It probably marked the death of a massive star as it collapsed into a black hole.
It has a so-called redshift of 6.29, which translates to a distance of about 13 billion light-years from Earth.
Used by astronomers to measure cosmic distances, redshift refers to the extent to which light is shifted towards the red part of the electromagnetic spectrum during its long journey across the Universe. The greater the distance, the higher the redshift.
Record distance
"This burst smashes the old distance record by 500 million light-years," said Dr Daniel Reichart, of the University of North Carolina, US, who has been leading the measurement of its distance..."
have to look out for technical reports on this by Daniel Reichart,
or Keith Mason, or Nial Tanvir.
Most distant cosmic blast sighted
"Astronomers have witnessed the most distant cosmic explosion on record: a gamma-ray burst that has come from the edge of the visible Universe.
Gamma-ray bursts are intense flares of high-energy radiation that appear without warning from across the cosmos.
They can release as much energy in a few minutes as our Sun will emit in its expected 10-billion-year lifetime.
The blast was observed by the Swift space telescope and by a number of ground-based observatories.
The latest, record gamma-ray burst was detected on 4 September, 2005, and lasted about three minutes. It probably marked the death of a massive star as it collapsed into a black hole.
It has a so-called redshift of 6.29, which translates to a distance of about 13 billion light-years from Earth.
Used by astronomers to measure cosmic distances, redshift refers to the extent to which light is shifted towards the red part of the electromagnetic spectrum during its long journey across the Universe. The greater the distance, the higher the redshift.
Record distance
"This burst smashes the old distance record by 500 million light-years," said Dr Daniel Reichart, of the University of North Carolina, US, who has been leading the measurement of its distance..."
have to look out for technical reports on this by Daniel Reichart,
or Keith Mason, or Nial Tanvir.
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