Spinning pulsar, got to slow down

(This headline was my original choice for the article, which was understandably rejected by my editors. So, you get to read it here instead.)

Pulsars are rapidly-spinning neutron stars, the very small dense remnants of stars at least 8 times more massive than the Sun. Their pulses are intense beams of light that sweep across our field of view each time the neutron star rotates. A pulsar’s rotation slows down over time, though, and some researchers in the UK have proposed a simple physical model that refines the most widely accepted theory.

Observations of the matter expelled by the initial supernova can be used to estimate the age of the pulsar; those numbers can be compared to age estimates based on its spin slowdown. In some cases, these estimates match reasonably well, but in others, they give wildly different results, differing by thousands of years at the extreme. The researchers’ model began with a different assumption: that the superfluid comprised a higher fraction of the core before things start to cool down. The result is pinning: the vortices in the superfluid stick to one spot relative to each other. That means the superfluid’s rotation rate remains the same, while the rest of the pulsar continues to slow down. [Read more….]

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