Pulsar
PSR B1931+24 "... looks like a normal pulsar for about a week and then 'switches off' for about one month before producing pulses again. [..] this pulsar slows down more rapidly when the pulsar is on than when it is off. [.. the] way it slows down must have to do with the radio energy and the things that cause it, and the extra slow-down can be explained by a wind of particles leaving the pulsar's magnetic field and slowing down the speed at which it turns.