Astronomers have detected what is believed to be the most distant object in the universe - the remnants of a star that exploded with a burst of high-energy particles more than 13 billion years ago. Scientists hope the ancient gamma ray blast will shed new light on the formation of the universe.
The 10 second gamma ray burst, detected in April 2009, occurred at a distance of 13.14 billion light years from Earth, far beyond any known quasar or galaxy.
Antonino Cucchiara is an astronomer and post-doctoral fellow at the University of California, Berkeley. He was part of the team that pinpointed the ancient flash of light.
Cucchiara notes that scientists believe the "Big Bang" event that created the universe occurred 13.6 billion years ago. The 090429 gamma-ray burst took place a relatively short time afterward, when the rapidly expanding universe was only 520 million years old and just 10 percent of its current size.
"If you imagine that the age of the universe is like the age of the man, and the average man can live up to 100 years, this object was exploded when the universe was like a five year old kid," said Cucchiara. "So, very early in the universe."
Experts say gamma ray bursts - the brightest explosions in the cosmos - are detected by telescopes and other instruments at the rate of one or two per day.
In the case of 090429, astronomers at Pennsylvania State University used data from the Swift satellite, operated by the U.S. space agency NASA, to pinpoint its location in the sky. Scientists then used a combination of ground-based optical and infrared telescopes to confirm the distance of the explosion.
Astronomer Antonino Cucchiara says the orbiting Hubble Space Telescope captured images of the flash.
"It’s essentially a bright, point-like star source in our digital images that becomes fainter and fainter with the pass [passage] of time." he said.
Cucchiara says the massive cosmic explosion marked the death of a giant star 30 or 40 times the size of our sun. A star dies when the nuclear fuel at its core is spent; the star then collapses, emitting a blast of gamma rays that can be detected billions of light years away by Earth-based astronomers.
Cucchiara says he and his colleagues hope the new data tell them something about the forces that led to the formation of giant stars and the universe.
“We know that long gamma ray bursts like this one are formed by very massive star," said Cucchiara. "So that tells you already that such stars should exist at a very early time in the universe. And since we don’t know much about how stars were formed in the first place at the beginning of the universe and we don’t know how galaxies were formed, having this kind of information from gamma ray bursts is very important. It’s crucial.”
Cucchiara and his colleagues presented their report on the ancient gamma ray burst at the annual meeting of the American Astronomical Society in Boston.
