Pulsars are actually pretty noisy. Starquakes, infalling matter and braking due to drag on the magnetic field jink the rotational frequency around a lot, compar

Pulsars are actually pretty noisy. Starquakes, infalling matter and braking due to drag on the magnetic field jink the rotational frequency around a lot, comparable to a good clock (you could probably compensate for the braking effects, but the quakes are another matter).