Periodic nulls in pulsar B1133+16

Numerous studies of the brightest Cambridge pulsar, B1133+16, have revealed little order in its individual pulses, apart from a weak 30-odd-rotation-period fluctuation feature and that some 15% of the star's pulsars are "nulls." New Arecibo observations confirm this fluctuation feature and that it modulates all the emission, not simply the "saddle" region. By replacing each pulse with a scaled version of the average profile we were able to quench all subpulse modulation and thereby demonstrate that the star's "null" pulses exhibit a similar periodicity. An unabridged analysis of periodic nulling (using the techniques in this paper) in pulsar B1133+16 is in Herfindal & Rankin (2007).