Pulsars - fastest spin rate

For pulsars whose spin rates have been accurately measured, the fastest-spinning is PSR B1937 + 214, which was discovered by a group led by Donald C. Backer in November 1982. It is in the minor constellation Vulpecula (the Little Fox), 11,700 light years distant and has a pulse period of 1.5578064949 millisec, which is equivalent to a spin rate of 641.9282518 revolutions per sec.