Aussie astrobophins believe they have developed one of the more unusual strands in the universe – shiny pulsars.
Neutron stars rotate rapidly, emitting electromagnetic energy pulses at regular intervals. Sometimes lightning shakes, speeding up and then suddenly slowing down for a few seconds, leaving scientists puzzled.
The strange behavior known as the "bug" is best observed in Vela Pulsar, a neutron star located 1000 light-years away. About 5 percent of pulsars are known to collide, but Vela Pulsar fails once every three years.
A group of scientists – led by a team at the Australian University of Monash – compared data taken from a glitch event in 2016 using data from the Mount Pleasant Observatory in Tasmania. They found that the star's rotation rate increased by about 16 microhertz, a small amount over 30 seconds or more, according to a paper published on Nature Astronomy on Monday.
That means "about a millionth of a million," said Gregory Ashton, the first author of the article and an assistant professor of astrophysics at Monash University The register,
"Just before the problems, we noticed that the star appeared to be slowing down before turning back. In fact, we have no idea why this is and this is the first time this has been seen," he added.
The problem can be explained by the rendering of a neutron star as three separate parts. The outer crust is made up of solid neutrons that remain fixed in place. However, the inner crust and nucleus behave more like a superfluid where neutrons can move and move around. Problems are thought to be caused when the excess angle of neutrons in the inner crust is transferred to particles in the outer crust.
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The additional impulse temporarily increases the speed of rotation of neutron stars such as Vasa Pulsar. However, what triggers this process is not well understood. After the error, the rotational speed of the star shuts off, explained Paul Laski, a professor of astrophysics at Monash University. "A second superfluid soup moving in the core is leveled to the first, which causes the star to rotate slowly."
More puzzling is the fall in the speed just before waking up, something researchers have called an "anti-bug".
"To our knowledge, this was not foreseen," they conclude. "We speculate that it may be a statistical fluctuation corresponding to the total noise fluctuations, and we speculate that such fluctuations drive the differential lag between the superfluidity and the crust above its critical value, thus triggering the problems."
"We hope to spark discussion about these results in the community. There are many ideas that could explain observations by directly testing models on the data itself. We hope to quantify how these models stack up against the data." Ashton said.
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