Fast Spinning Neutron Star Has Strange Cosmic Glitch

Neutron stars spin around at a phenomenal pace. Now, though, the physics behind these extraordinary stellar objects may have become a bit more puzzling. Researchers have discovered a new kind of glitch in the cosmos in the rotation of a neutron star.

Neutron stars are some of the densest objects in the observable universe. The high densities that these stars possess are only found in similar densities in their close cousins, black holes. In fact, a typical neutron star packs as much mass as half a million Earths within a diameter of only about 12 miles. A mere spoonful of neutron star material would weigh about one billion tons--that's a lot of mass.

These stars aren't just known for their mass, though. They're also known for their ability to rotate extremely rapidly--from a few revolutions per minute to as fast as several hundred times per second. Yet there's sometimes a glitch when it comes to these stars. Occassionally, stars start rotating more quickly.

In this latest study, astronomers discovered a glitch in a special type of neutron star called a magnetar. This ultra-magnetized neutron can exhibit dramatic outbursts of X-rays than can sometimes affect Earth's atmosphere. Yet it wasn't a speed-up glitch. Instead, researchers saw the magnetar actually rotate more slowly, something that they've dubbed an "anti-glitch."

The magnetar with this glitch is called 1E 2259+586 and is located roughly 10,000 light years away in the constellation of Cassiopeia. Monitored by the Swift X-ray telescope, the magnetar was being studied to try to detect the occasional giant X-ray explosion. Yet the researchers found something different when examining their data.

"I looked at the data and was shocked-the neutron star had suddenly slowed down," said Rob Archibald, lead author, in a news release. "These stars are not supposed to behave this way."

In addition to the slowing rotation, there was also a large increase in the X-ray output of the magnetar. It's very possible that something in the internal structure of the magnetar changed in order to cause this slower rotation and the accompanying X-rays. Currently, the insides of a magnetar are a celestial mystery to astronomers.

The findings could have important implications for learning about these insides, though. The anti-glitch strongly suggests previously unrecognized behavior inside neutron stars, possibly with pockets of superfluid rotating at different speeds inside. Currently, the researchers are hoping to better understand the internal structure of magnetars and other stars.

The findings are published in the journal Nature.