\pm 0.007$ c s$^{-1}$, respectively, for the first and second epochs; the overall count-rate is constant to within 0.75% (the second observation is $1.5\sigma$ fainter than the first). Thus, the $3\sigma$ limit on any increase in the pulsar luminosity in response to energy input from the glitch is $<1.2 \times 10^{30}$ erg s$^{-1}$ or $\Delta T \sim 0.2\%$, 35 days ($3 \times 10^6$ s) after the event[^2]. The lower half of Figure 5 shows the difference between the two observations as a function of pulse phase, where the second dataset has simply been scaled by the ratio of the total integration times; no single bin has a discrepancy exceeding 1.5 sigma. This constancy in both the pulsed luminosity and pulse profile set interesting constraints on the glitch mechanism (see §6.4).

Changes in the Nebula
=====================

While the primary energy release from a glitch must be within (or on the surface of) the neutron star, the response of the star’s magnetosphere could result in the release of energy to the synchrotron nebula, triggering changes in its morphology and/or brightness. Even without the stimulus of a glitch, the optical wisps of the Crab Nebula near the pulsar have been shown to change 