Unprecedented' Cosmic Blast in Distant Galaxy Spawns Intergalactic Mystery

Astronomers are puzzling over an extraordinary cosmic blast in a distant galaxy. NASA has called the explosion "unprecedented."

The gamma-ray explosion was observed on March 28 by NASA's Swift satellite. Flaring from such an event usually lasts a couple of hours. (For a stunning visual simulation of another type of cosmic blast, check out The Blaze's related coverage.)

Scientists say the March 28 blast is unusual because the effects are long-lasting. More than a week later, they continue to see high-energy radiation spiking and fading at the source.

Science Mag has more details:

Astronomers have observed possibly the biggest blast ever seen in the cosmos. When NASA's SWIFT space observatory first spotted it 10 days ago, observers thought it was a massive star blowing up as a supernova and expected it to fade within hours or even minutes. But the high-energy radiation from the source has shown no sign of dying down, which suggests that astronomers may have caught a star in the process of being ripped to shreds by a black hole.

The blast is actually a series of bursts, like a string of firecrackers going off one after another. "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," says Andrew Fruchter of the Space Telescope Science Institute in Baltimore, Maryland. "This is truly extraordinary."

SWIFT's Burst Alert Telescope detected the source of the bursts on 28 March. The Hubble Space Telescope took an image of the source on 4 April, which located the explosions at the center of a galaxy 3.8 billion light-years away. On the same day, NASA's Chandra X-ray Observatory took a picture of the source by pointing at it for 4 hours. That image also showed that the source of the bursts was at the center of the galaxy imaged by Hubble.

Popular Science has a theory:

So astronomers now have a theory. It’s quite possible that a star was minding its own business when it wandered too close to the galaxy’s central black hole. The intense forces generated by the black hole began to tear the star apart, causing infalling gas to begin streaming into it in a particle jet. This spawned an outflowing jet along the black hole’s rotational axis, and that jet is pointed directly at us from billions of light years away.

Since the explosion, the Hubble Space Telescope and Chandra X-ray Observatory have focused on the aftermath. Hubble will observe if the galaxy's core changes brightness in the coming days.

The galaxy is 3.8 billion light years from Earth. A light year is about 6 trillion miles.

The Associated Press contributed to this report.