An abrupt disturbance in the regular train of pulses from a pulsar, appearing as a sudden decrease in the pulsar's period (i.e. a speed-up in rotation), accompanied by an increase of the spin-down rate which gradually returns to its former value over a few weeks or months. Glitches tend to occur in younger pulsars whose rate of spin is slowing rapidly, notably the Crab Pulsar and Vela Pulsar. They are believed to be caused by the sudden release of stress energy either in the crust (a starquake) or between the crust and the superfluid interior.
Subjects: Astronomy and Astrophysics.