DIFFERENCES IN THE COOLING BEHAVIOR OF STRANGE QUARK MATTER STARS ANDNEUTRON-STARS

The general statement that hypothetical strange quark matter stars coo l more rapidly than neutron stars is investigated in greater detail. I t is found that the direct Urea process can be forbidden not only in n eutron stars, but also in strange-matter stars. In this case, strange- matter stars cool slowly and their surface temperatures are more or le ss indistinguishable from those of slowly cooling neutron stars. We in vestigate the case of enhanced cooling again. We find that strange-mat ter stars cool significantly more rapidly than neutron stars within th e first similar to 30 yr after birth. This result may become particula rly interesting if continued observation of SN 1987A reveals the tempe rature of the pulsar that may reside at its center.