Cosmic blast in distant galaxy leaves NASA baffled

"Astronomers say they have never seen such a bright, variable, high-energy, long-lasting burst before. Usually, gamma-ray bursts mark the destruction of a massive star, and flaring emission from these events never lasts more than a few hours," reads statement from NASA.

"More than a week later, high-energy radiation continues to brighten and fade from its location," it adds.

The Hubble Space Telescope (HST) along with its Swift satellite and Chandra X-ray Observatory have been put to work to examine the rare phenomenon.

Remarkable phenomenon observed
What took place was not a single incident, rather a series of X-ray explosions.

The first blast was spotted by Swift's Burst Alert Telescope on March 28 in the constellation Draco.

On April 4, the Hubble telescope pinpointed the source of the explosion at the center of a galaxy which is 3.8 billion light-years away from Earth.

Astronomers later made an exposure of the baffling source for four hours using Nasa's Chandra X-ray Observatory.

The result was an image 10 times more precisely than the Swift telescope.

NASA said that the source has brightened more than five times since April 3. This increase in brightness- the relativistic beaming- occurs "when matter moving close to the speed of light is viewed nearly head on."

Black hole connection suspected
Going by a NASA statement, astronomers have got hold of a plausible cue regarding what led to this rare event.

According to them, the blast occurred "when a star wandered too close to its galaxy's central black hole."

The gravitational force might have tore the star and released gases that are still falling towards the black hole.

"According to this model, the spinning black hole formed an outflowing jet along its rotational axis. A powerful blast of X- and gamma rays is seen when the jet is pointed in our direction,” the statement claimed.

Andrew Levan, from the University of Warwick, who headed the Chandra observations said "the best explanation at the moment is that we happen to be looking down the barrel of this jet".

"The fact that the explosion occurred in the center of a galaxy tells us it is most likely associated with a massive black hole. This solves a key question about the mysterious event,” said Neil Gehrels, the lead scientist for Swift at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

NASA said that the source has brightened more than five times since April 3. This increase in brightness- the relativistic beaming- occurs "when matter moving close to the speed of light is viewed nearly head on".

Andrew Fruchter, of the Space Telescope Science Institutein Baltimore, tagged the event as phenomenal.

"We know of objects in our own galaxy that can produce repeated bursts, but they are thousands to millions of times less powerful than the bursts we are seeing now," he said.