The fact that some of these neutron stars would have to be spinning at a rate of many revolutions per second has not deterred astronomers from continuing to accept and develop the model, even after pulsars with millisecond periods were discovered. But the short periods have not been the only challenge to the neutron star lighthouse model. Astronomers and astrophysicists have been pushed to the limit as they contrive more and more intricate neutron star models to explain what they are seeing, and for some behaviors they have no explanation. Timing of averaged profiles is similarly precise. Single-pulse Variability Timing and shape of individual pulses vary considerably.
Individual pulses occur successively earlier and earlier within the averaged profile.
For certain drifiting pulsars, drift rate abruptly shifts in value. Or drift may be random with occasional recurring patterns. Polarization Changes Polarization parameters vary within individual pulses, but time-averaged profile of polarization is constant. About half of observed pulsars exhibit micropulses within individual pulses. Micropulses typically last a few hundred microseconds.