Statistical Equilibrium Model Atmospheres for Early-Type Stars. III. Hydrogen and Helium Continua

Results are presented for model atmospheres allowing for departures from LTE in hydrogen, helium, and ionized helium on the temperature range 100000 K «= Teff «= 360000 K. The essential simplifying assumption we make is that all radiative bound-bound transitions are in detailed balance. While this assumption is valid in certain physical circumstances, it is not everywhere correct, and the results de- rived here should be regarded as oniy exploratory As was the case in earlier results, the departures we find are quite small and have only small effects upon the emergent energy distribution, so that LTE appears to be a fairly adequate approximation in the calculation of the continuous energy distribution. No information concerning line formation can be inferred from the present results