A causal model of radiating stellar collapse

We find a simple exact model of radiating stellar collapse, with a shear-free andnon-accelerating interior matched to a Vaidya exterior. The heat flux is subject to causalthermodynamics, leading to self-consistent determination of the temperature T . We solve for Texactly when the mean collision time c is constant, and perturbatively in a more realistic case ofvariable T_c. Causal thermodynamics predicts temperature behaviour that can differ significantlyfrom the predictions of non-causal theory. In particular, the causal theory gives a higher centraltemperature and greater temperature gradient