Scientists Detect a Massive Thermonuclear Explosion From Outer Space

The blast produced an intense ray of X-rays that traveled some 11,000 light-years to our cosmic neighborhood. NASA's Goddard Space Flight Center/Chris Smith, USRA

Not every bang that happens in space is a Big Bang.

In fact, the cosmos crackles and pops all the time. There are kilanovas — which are a kind of glitter-bomb, spewing gold and platinum. And black hole collisions that scatter matter and energy into the universe. And let's not forget the celestial stunner that is the supernova — the explosive swan song of a star. There's even a more intense variant called a hypernova, one of the most powerful explosions ever detected.

Then there's the massive thermonuclear explosion that NASA scientists detected last August. It came from a very distant galaxy, the space agency notes. But the blast was so vigorous, it produced an X-ray beam that was picked up by the NICER telescope on the International Space Station.

In fact, the explosion took just 20 seconds to produce as much energy as our sun does in 10 days. And it's likely the biggest blast of X-ray radiation we've ever detected.

"This burst was outstanding," astrophysicist Peter Bult notes in the NASA statement.

'Lighthouse of the universe'

What kind of object goes so massively thermonuclear that it rattles scientists a galaxy away? According to research published recently in The Astrophysical Journal Letters, a pulsar some 11,000 light-years away dubbed J1808 likely brought the boom. That's a kind of neutron star that spins rapidly — and as it turns, a very intense beam of light enters our line of sight. As a result, a pulsar is often dubbed the "the lighthouse of the universe."

In this case, the star built its own very big bomb, the result of helium sinking beneath its surface and fusing into a ball of carbon.

"Then the helium erupts explosively and unleashes a thermonuclear fireball across the entire pulsar surface," Zaven Arzoumanian, who co-authored the paper, explains.

Imagine a bomb so powerful, it engulfs the entire surface of our sun. Indeed, the blast was so massive, it seemed to take a breath between two very distinct ignitions.

The initial blast, researchers noted, blew that massive helium layer into space. There was a second burst, roughly 20 percent as bright as the first, that followed.

And while scientists aren't quite sure what caused the second blast, they do expect to get a lot of buck from this bang.

"We see a two-step change in brightness, which we think is caused by the ejection of separate layers from the pulsar surface, and other features that will help us decode the physics of these powerful events," Bult explains.

Here's a NASA video illustrating how scientists believe the thermonuclear blast developed: