DOUBLET 2800 MGII IN CLOSE BINARY-SYSTEMS

It is shown that the emission ultraviolet doublet 2800 Mg II in radio stars, actually in close binary systems, do not have chromospheric origin, but is generated in the space between the components of the system, filled by clouds or streams of two types - emission (A) and absorption (B). It is shown also that the strongly deformed or distorted forms of short wavelength halfs of emission profiles k and h Mg II (Figures 1 and 4) are a result of the absorption in the intercomponent space, by clouds B. Both qualitative and quantitative criteriums are obtained for these clouds A and B, at which the observed forms of emission profils k and h Mg II may be explained. Particularly, the hydrogen atoms in absorption clouds B must be ionized not strongly or be with concentrations on three orders less than in emission clouds of type A.