Glitch (astronomy) - Cause

Cause

While the exact cause of glitches is unknown, they are thought to be caused by an internal process within the pulsar. This differs from the steady decrease in the star's rotational frequency which is caused by external processes. Although the details of the glitch process are unknown, it is thought that the resulting increase in the pulsar's rotational frequency is caused by a brief coupling of the pulsar's faster-spinning superfluid core to the crust, which are usually decoupled. This brief coupling transfers angular momentum from core to the surface, which causes an increase in the measured periodicity. It is thought that the coupling could be caused by a breaking of the pulsar's magnetic dipole, which would apply a torque to the crust causing a brief coupling between the two parts.