2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/5206MWC 560 and other peculiar symbiotic binary, CH Cyg, have been classified as the prototypes of the new subclass of symbiotic systems - propellers, with accretion onto a magnetic white dwarf being the source of activity. The companion of the hot component in this model should demonstrate stellar wind with relatively high mass-loss. It can be expected rather a late AGB, Mira or semiregular variable (SR) than any normal red giant.Our analysis performed for the I band shows that the M giant probably belongs to such kind of stars and pulsates with a period of about 5 months.4 pages, 2 figures, to appear in the proceedings of "Symbiotic stars probing stellar evolution", R.L.M.Corradi, J.Mikolajewska, T.J.Mahoney eds., 2002, ASP Conference Series, in pressAstrophysicstext