Determination of Mass Loss Rates of Symboitic Binaries

The symbiotic binary is a special system, consisting of a hot early type star and a cool late type supergiant with strong stellar wind, which forms an expanding envelope. In the expanding envelope, the orbital motion of the hot star produces P-Cygni type lines which have periodic variation profiles. The mass loss rate from the stellar wind of the supergiant can be determined by analysis of these lines. In this paper, we discuss the use of the theory of moving atthospheres to determine the mass loss rate by caculating the line formations of symbiotic binaries. We develope a method to calculate the multiple transitions in the hydrogen and helium mixture gases and treat the distribution of the density as non-radial distribution resulting from the orbital motions. The results show the key characteristics of periodic variations of the line profile of symbiotic binaries. In iddition, we have made an improvement of the linearization -separation technique, a method used in the carculation of the Non-LTE atmosphere models.