An image of the Vela pulsar (which lies at the heart of the Vela supernova remnant) in which glitching has been observed. The pulsar itself is the bright white spot at the centre of the hot gas, and a jet powered by its rotational pole is also observed in this Chandra X-ray Observatory image. (Courtesy: NASA/CXC/PSU/G Pavlov et al.)

Pulsars are known to be the most precise cosmic timekeepers, but occasional "glitches" or a sudden increase in their spin rate disrupts the stars' otherwise regular behaviour. A new study of the glitching process by an international team of researchers suggests that superfluid matter in the core of a pulsar may cause the poorly understood effect. The work combines radio and X-ray data to determine pulsar masses, and successfully explains glitches that are documented in 45 years' worth of observational data.

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Fermi-LAT sky map with the celestial neighborhood of the newly discovered pulsar PSR J1906+0722. The color scale shows the gamma-ray intensity. [Knispel/AEI/NASA/DOE/Fermi LAT Collaboration]

Since the release of the second Fermi-LAT catalog in 2012, astronomers have been hunting for 3FGL J1906.6+0720, a gamma-ray source whose association couldn’t be identified. Now, personal-computer time volunteered through the Einstein@Home project has resulted in the discovery of a pulsar that has been hiding from observers for years.

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Some long-duration gamma-ray bursts are driven by magnetars
8 July 2015

Observations from ESO’s La Silla and Paranal Observatories in Chile have for the first time demonstrated a link between a very long-lasting burst of gamma rays and an unusually bright supernova explosion. The results show that the supernova was not driven by radioactive decay, as expected, but was instead powered by the decaying super-strong magnetic fields around an exotic object called a magnetar. The results will appear in the journal Nature on 9 July 2015.

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Artist's impression of a pulsar, including the extreme magnetic field surrounding the dense stellar object. Credit: NASA

For the first time, the mass of a binary pulsar pair has been precisely measured, but it was a race against time before the extreme gravitational warping of spacetime caused one of the dense objects to blip out of view.

Pulsars are rapidly-spinning neutron stars that generate powerful beams of radiation from their poles. Neutron stars are the stellar husks of long-dead stars that ran out of hydrogen fuel and collapsed under gravity to create a mass of degenerate matter.

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An artist's impression of a neutron star. The cosmic object's 'nuclear pasta' would be located between the crust and the outer core of the neutron star. Credit: NASA/Dana Berry

The crusts of neutron stars — cosmic cousins of black holes — possess a weird form of matter known as "nuclear pasta."

Now, scientists have found that nuclear pasta may be even stranger than previously thought, forming defects that bond pieces together into complex, disorderly shapes. This complex nuclear pasta could ultimately doom the powerful magnetic fields seen from neutron stars, researchers say.

A neutron star, like a black hole, is a remnant of a star that died in a catastrophic explosion known as a supernova. Neutron stars are typically small, with diameters of about 12 miles (19 kilometers) or so, but they are so dense that a neutron star's massmay be about the same as that of the sun. A chunk of a neutron star the size of a sugar cube can weigh as much as 100 million tons, making neutron stars the densest objects in the universe besides black holes.

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