A massive glitch in an old pulsar

Abstract

Pulsars normally spin down steadily due to the braking torque applied by the intense magnetic field of the neutron star¹. However, several of them display irregularities in rotation rate of two main types: random fluctuations, known as timing noise, and discrete discontinuities in rotation rate, known as glitches. Observations of these irregularities provide valuable information on the internal structure of neutron stars. Unfortunately glitches occur infrequently and large glitches have been observed in only two pulsars. Here, we describe a recent series of observations in which the relatively old pulsar PSR0355 + 54 has been seen to suffer two glitches, the second of which is the largest observed in any pulsar and provides a valuable opportunity for the study of the recovery of the interior of a neutron star following such a large perturbation.