Beta decay in quark stars

It is shown that the energy flux, ET, from quark matter in "quark stars" due to the simple URCA process is roughly comparable to that from pion condensates even when quark-quark interaction (QQI) effects are ignored. The form of ET is then independent of the ambiguous electron density and the effective gluon coupling in the "quark star" and accounts for the neutrino in momentum conservation. It is concluded that one need not invoke QQI to explain the recent null x-ray detection of "neutron"-star surface temperatures by the presence of a quark core.