May 26, 2011

Scientists Observe Object At Record Breaking Distance

A cataclysmic explosion of a huge star near the edge of the Universe may be the most distant object ever observed.

Scientists believe the blast occurred about 520 million years after the Big Bang.

This means its light has taken 13.14 billion years to reach Earth.

Astronomers refer to the event, which was observed by using NASA's Swift space observatory, as GRB 090429B.

The "GRB" stands for "gamma-ray burst", which is a sudden pulse of very high-energy light that the telescope is tuned to find on the sky.

"It would have been a huge star, perhaps 30 times the mass of our Sun," said lead researcher Dr Antonino Cucchiara from the University of California, Berkeley.

"We do not have enough information to claim this was one of the so-called 'Population III" stars, which are the very first generation of stars in the Universe. But certainly we are in the earliest phases of star formation," he told BBC News.

Swift originally detected the burst in April 2009.  The scientists spent two years examining data to see if the burst really was a record-breaker. 

"The more we examined this burst, the better it looked." University of Warwick astronomer Dr Andrew Levan said in a statement.

"The race to find distant objects stems from the desire to find and study the first stars and galaxies that formed in the Universe, in the first few hundred million years after the Big Bang."

"By looking very far away, because the light takes so long on its journey to reach the Earth, astronomers are effectively able to look back in time to this early era.  Unfortunately, the immense distances involved make this very challenging."

The scientists used the Swift satellite, the Gemini North Observatory and the Hubble Space Telescope during their study.

"This GRB shows us that there is a lot of action going on in the Universe which we can't currently see," Professor Nial Tanvir, from the University of Leicester and the leader of the Hubble Space Telescope part this research program, said in a statement.

"Our observations show us that even the Hubble Space Telescope is only seeing the tip of the iceberg in the distant Universe".

The research has been accepted for publication in the Astrophysical Journal in a paper entitled "Photometric Redshift of z ~ 9.4 for GRB 090429B. 2011" with former Penn State graduate student Antonino Cucchiara as first author and Dr Andrew Levan from the University of Warwick as its second author.

Image Credit: Gemini Observatory / AURA / Levan, Tanvir, Cucchiara


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