Scientists snap most distant object in the universe – 13 billion light years away

Scientists snap most distant object in the universe – 13 billion light years away

Astronomers have snapped a picture of the most distant object ever seen in the universe – a titanic burst of energy from a dying star 13 billion light years away.

By Richard Alleyne, Science Correspondent
Last Updated: 8:11PM BST 28 Apr 2009


The 'gamma ray burst' is so far away that its light has taken almost the entire age of the universe to reach us Photo: NASA

The "gamma ray burst" is so far away that its light has taken almost the entire age of the universe to reach us.

When the light began its journey, travelling at 186,000 miles per second, only 640 million years had passed since the Big Bang that marked the dawn of creation.

The event, designated GRB 090423, was first detected by the American space agency Nasa's Swift satellite, which is designed to spot gamma ray bursts.

After Swift recorded an initial blast of gamma and X-rays, ground-based telescopes swivelled to aim at the same point in the sky and observed a fading afterglow of infra-red light.

Scientists believe the burst was caused by a massive star collapsing and exploding at the end of its life, leaving a black hole.

Dr Nial Tanvir, from the University of Leicester, said: "This is the most remote gamma-ray burst ever detected, and also the most distant object ever discovered – by some way."

Swift detected a 10 second burst of gamma rays from GRB 090423 at 8.55am UK time on April 23.

It quickly pivoted to bring its optical and X-ray telescopes to bear on the object. Although Swift was able to pick up a fading pulse of X-rays, it saw nothing in visible light. This in itself suggested that the burst was very distant, since light from a far away object is shifted in wavelength towards the red end of the spectrum until it becomes invisible.

Twenty minutes later the British Infra-red Telescope on Mauna Kea, Hawaii, located a source of light beyond the optical range at the same spot pinpointed by Swift. This was the infra-red "afterglow" of the gamma ray burst.

Other ground-based telescopes around the world were rapidly aimed in the same direction and confirmed the discovery.

When scientists calculated the afterglow's "redshift" – the degree to which the wavelength of light from the object was shifted in the red direction – they realised the gamma ray burst had broken all distance records.

US astronomer Professor Edo Berger, from the Harvard Smithsonian Centre for Astrophysics in Cambridge, Massachusetts, who also studied the burst, said: "I have been chasing gamma-ray bursts for a decade, trying to find such a spectacular event.

"We now have the first direct proof that the young universe was teeming with exploding stars and newly-born black holes only a few hundred million years after the Big Bang."

Gamma-ray bursts are the most luminous explosions in the universe and are the afterglows of dying stars.

http://www.telegraph.co.uk/scienceandtechnology/science/space/5237960/Scientists-snap-most-distant-object-in-the-universe---13-billion-light-years-away.html