A 143 MILLISECOND RADIO PULSAR IN THE SUPERNOVA REMNANT S147

We report the discovery of a 143 ms pulsar, PSR J0538+2817, in the sup ernova remnant S147 (0180.0-1.7). The pulsar is located 40' west of th e center of S147, well within its evolved, roughly circular radio stru cture. An upper limit to the pulsar's age of 6x10(5) yr is consistent with the age of the remnant, estimated to be similar to(8 x 10(4))-(2 x 10(5)) yr. A dispersion measure-derived distance to PSR J0538+2817 i s similar to 1.8 kpc, in reasonable agreement with a 0.8-1.6 kpc dista nce estimate for S147. These data provide sufficient evidence to hypot hesize that the two objects are physically related and form a new asso ciation between a radio pulsar and an old supernova remnant.