750-DAYS VARIABILITY OF THE CH CYG

Abstract

Using the AAVSO database of photometric observations, the light curve of the symbiotic star CH Cyg was constructed for 1963-2021. Analysis of the light curve showed that all minima correspond to variations of ∼750 days, excluding the period of the outburst of stars.Periodic analysis of the brightness and radial velocities of absorption lines was carried out using the Fourier scargle analysis.The light curves for 1966-1976 and 2000-2005 revealed a period of 750 days, corresponding to the relatively quiet state of the star, and 751 days for the velocities of the absorption lines of the red giant. The radial-velocity curve is ahead of the light curve by 0.30 phases.