Modeling Stellar Atmospheres

Stellar atmosphere represents a region of large gradients in thephysical variables such as the temperature, gas pressure and theradiation field. It is also where the stellar material becomesoptically thin with the result that the radiation field is nolonger strongly coupled to the local environment. As such, stellaratmospheres are comparatively difficult to model. A meaningfulinterpretation of stellar spectra, however, is only possible withthe assistance of consistent models. Consequently, much effort hasbeen devoted to the construction of such models over the pastfifty years.