Glitching neutron star opens up to researchers

Neutron stars are among the densest objects in the Universe. They rotate extremely fast and regularly— until they don’t. Occasionally, these neutron stars start to spin even faster, caused by portions of the inside of the star moving outwards. It’s called a ‘glitch’ and it’s a rare glimpse into the interior of these mysterious objects.

Researchers from Monash University, the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), McGill University in Canada, and the University of Tasmania, have studied the interior of the Vela Pulsar, a neutron star in the southern sky that is 1,000 light years away.

Dr Paul Lasky, an ARC Future Fellow from the Monash School of Physics and Astronomy, and a member of the OzGrav team that studied Vela, says that for the first time, the scientists have got a glimpse into the interior of the Vela Pulsar—revealing that the inside of the star actually has three different components.

Their observations suggest a slower spinning core of superfluid neutrons acts like a clutch which slows the fast spinning star back down to regularity. Although this had been partly predicted by previous theoretical work, the researchers made another observation which defies explanation—immediately before the glitch, they noticed that the star seems to slow down its rotation rate before spinning back up.

Dr Greg Ashton, also from the Monash School of Physics and Astronomy, and a member of OzGrav, says that the research team currently has no idea why this is, and it’s the first time it has ever been seen. But they speculate it is related to the cause of the glitch and hope their research will spur some new theories on neutron stars and glitches. OzGrav is administered by Swinburne University.

	“VELA IS FAMOUS NOT ONLY BECAUSE ONLY 5% OF PULSARS ARE KNOWN TO ‘GLITCH’, BUT ALSO BECAUSE VELA GLITCHES ABOUT ONCE EVERY THREE YEARS, MAKING IT A FAVOURITE OF ‘GLITCH HUNTERS,” SAYS DR GREG ASHTON

 

Image: Greg Ashton (left) and Paul Lasky (right). Image Credit: Carl Knox, ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav)