1995A&A...300..189L

A short description of the behaviour of the long-period (P=5700 days) peculiar symbiotic binary CH Cyg during 1992-1994 is given. Photometric UBV observations carried out at Tartu, Torun and Olsztyn Observatories show the ever increasing brightness of the star, in particular, at shorter wavelengths. The spectrum is that of an M giant superimposed by the hot continuum and the emission lines of HI, HeI, CaII, FeII, [FeII], [SII], [Ne III] etc. The Balmer lines occasionally show additional blue- or red-shifted emission and/or absorption components with radial velocities ranging up to "Great Attractor" 700km/s. We interpret these results on the basis of the magnetic rotator model which assumes a magnetic (B∼10⁷Gs) rapidly rotating white dwarf as a hot component of the symbiotic system. According to this model, CH Cyg is now in a propeller state, with the white dwarf's rapidly rotating magnetosphere expelling outward the accreted matter and forming a quasi-stable envelope close to the white dwarf. The envelope probably is becoming optically thick. The Balmer line profiles indicate that the ejection of matter from the magnetosphere could take place in separate clumps.