Scientists record pulsar glitch for first time

After recording 640MB of data every 10 seconds for 19 hours a day over four years

Scientists from the University of Tasmania claim to have recorded a "pulsar glitch" for the first time ever.

Pulsars are rapidly rotating neutron stars which are sometimes formed after a supernova, when the core of a massive star condenses and collapses under the impact of gravity. Some pulsars abruptly change rotation rates for no apparent reason, and it's this sudden change of spin rate which is called a "glitch".

The first glitch was spotted by researchers in 1969 from Vela Pulsar, a neutron star sitting 1,000 light years away. Scientists have therefore studied a number of similar events since then to understand why this happens.

However, stargazers from Australia and New Zealand this week claim to have captured the glitch using a large radio telescope, showing what happens in the core of the star, something that has never been done before.

Being able to observe the glitch could offer new insights into how matter behaves in extreme environments, the scientists said.

Jim Palfreyman from the University of Tasmania's School of Natural Sciences worked with Professor John Dickey and colleagues at CSIRO Astronomy and Space Science and Auckland University of Technology in monitoring the Vela Pulsar over four years to capture the glitch.

"We knew a glitch happens about every three years, but like an earthquake, no one can predict one," Palfreyman said.

"We knew that if we could capture the glitch and the individual pulses it would provide us a wealth of information, including how matter behaves at extreme temperatures and pressures."

Discovered in 1968, the Vela Pulsar is a neutron star about 1000 light years away from Earth. Measuring 20km wide and rotating 11 times a second, it weighs one and a half times the mass of the sun.

"A cup full of the material from this neutron star would weigh as much as Mount Everest," Palfreyman added.

He recorded 640MB of data every 10 seconds for 19 hours a day for most days over four years using the University of Tasmania's 26-metre radio telescope at the Mount Pleasant Observatory in Tasmania and the 30m radio telescope at Ceduna in South Australia.

This observing apparently resulted in three petabytes of data collection.

"The way the glitch occurs is quite complex where the superfluid core of the star spins separately from the hard crust on the outside," Palfreyman explained. "Then after about three years the core grabs the crust, which is slowing down, and speeds it up, causing the glitch to occur.

"By capturing the glitch, and the individual pulses, it helps us to better understand the ‘equation of state', which is how matter behaves in different environments."

A pulsar is a laboratory that scientists simply couldn't recreate here on Earth. It has amazingly high temperatures and pressures and a massive magnetic field.

"The information gained might be useful in a variety of ways, such as building devices or machines that operate at extreme temperatures and pressures like a fusion reactor," he added.