On the theory of scattering photospheres

The problem is considered of the spectrum determination of a star in the photosphere of which, along with the true absorption, there takes place also radiation scattering. It is assumed that the ratio of the true absorption coefficient to the scattering coefficient is depth-dependent. The intensity of radiation emitted from the photosphere is expressed in terms of the function phi(eta, tau), which has been introduced earlier in solving the problem of diffuse reflection of light from an inhomogeneous medium. The case when the albedo of single scattering decreases exponentially with the optical depth is specially considered. For this case, the tables of auxiliary quantities, through which the radiation intensity is expressed, are presented. The obtained results may be applied to the photospheres of both hot and cold stars, in which the scattering centres are represented by free electrons and molecules, respectively