Formation of magnetized spatial structures in the Beta Lyrae system. III. Reflection of magnetically controlled matter in circumbinary structures in helium lines, in particular arising from metastable levels

Spatial gaseous structures in the Beta Lyrae system have been studied with the fact of change in the longitudinal component of the donor's magnetic field during the orbital period in mind. The investigation was based primarily on the study of the dynamics of the circumstellar structures surrounding the binary system as a whole. The special emphasis was placed on the study of complex helium lines, in particular those arising from metastable levels. A number of different observable facts from the ultraviolet to the red spectral region were analyzed. The configuration of the donor magnetic field is a factor that not only enhances mass transfer and influences the formation of spatial gas structures between stellar components but, to some extent, also affects the outflow of matter and the formation of external gas structures around this interacting binary system. Together with previous articles \citep{Skulskyy2020a, Skulskyy2020b}, the pieces of evidence of this work, confirming the reflection of magnetically controlled matter in circumbinary structures, define the basis for a coherent picture of the mass exchange between components and outflows of matter outwards