Editor's Summary

4 January 2007

How pulsars spin up

When a pulsar (a rotating neutron star) is born following the collapse of a massive star, it is spinning rapidly: initial rotation periods are of the order of 300 milliseconds. The common assumption is that this rotation is inherited from the progenitor due to conservation of angular momentum, but the established theories of stellar evolution cannot explain the distribution of spins needed for that to happen. Blondin and Mezzacappa have now identified an alternative source for this spin in the form of an instability in the collapsing supernovae. This mechanism generates a final spin period consistent with observations, even from spherically symmetric initial conditions.

Letter: Pulsar spins from an instability in the accretion shock of supernovae

John M. Blondin & Anthony Mezzacappa

doi:10.1038/nature05428

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