Rapid Contraction of Protostars to the Stage of Quasi-Hydrostatic Equilibrium. III Stars of 0.05, 1.0 and 20M⊙ with Energy Flow by Radiation and Convection

The evolution of collapsing protostars of 0.05, 1 and 20M0 is studied with computations which include radiative as well as convective energy flow, which has been entirely neglected in previous papers I and II. It is found that, when a shock wave which has been generated at the center reaches the outermost layers, the protostars flare up suddenly. The protostar of 1M 0 increases its luminosity from 5 X 10- 4 L0 to a peak value 6 X 103 L0 in a period of the order of 10 days. This peak value depends scarcely on the initial conditions. After the flare-up, a convective region grows inwards from the surface and the luminosity is kept at 1 X 10 3 L0 by convection until the star finally reaches a stage of wholly gravitational equilibrium. The luminosity at this stage is found to be very sensitive to the stellar mass, being 8L0 and 5 X 10 4 Lev for the protostars of 0.05 and 20M0, respectively. These computed values of the luminosity are high enough to cover the observations of infrared objects.