SPECTRAL INVESTIGATIONS OF THE SYMBIOTIC STAR CH CYGNI IN 2018

Abstract

The paper presents the results of a comparative analysis of the star's light curve with the spectrophotometric parameters of the Hα, Hβ, NaI doublets lines of the D1, D2 and HeI 5876 measured on the basis of highly resolved echelle spectra of the symbiotic star CH Cyg obtained in the 2018th ShAO telescope in 2018 using a modern light receiver. The results of the analysis showed that
the equivalent width and intensity of the Hα, Hβ and HeI 5876 emission lines increase with decreasing star brightness. Even at maximum brightness, the HeI 5876 line disappears. Changes in the values of equivalent width and intensities of the components of the Hβ line and the light curve V show the same character with the opposite phase. High-velocity wide absorption components with a velocity of up to 800 km/s were found in the Hβ and HeI 5876 lines. The NaI doublets absorption line proles show a two-component structure, and the change in depth (1 − I/I0) of the red components of the D1 and D2 lines indicates exactly the same feature as the brightness change V.