Jun 23
3C 58 or 3C58 is a pulsar (designation PSR J0205+6449) and supernova remnant (pulsar wind nebula) within the Milky Way. The object is listed as No. 58 in the Third Cambridge Catalogue of Radio Sources.
It is located 2° northeast of ε Cassiopeiae and is estimated to be 10,000 light-years away. Its rotation period is 65.715 ms (so PSR J0205+6449 does not belong to the class of millisecond pulsars).
The pulsar is notable for its very high rate of cooling, which is unexplained by standard models of neutron star formation. It is hypothesized that extreme conditions in the star's interior cause a high neutrino flux, which carries away the energy so that the star cools. 3C 58 has been proposed as a possible quark star (or strange star).