Evolution of asymmetries in the circumstellar disc of the Be/X-ray binary X Persei

We present spectroscopic observations of the Be/X-ray binary X Per obtained during the period December 2017 - March 2019 (MJD58095 - MJD58568). In December 2017 the H-alpha, H-beta, and HeI6678 emission lines were symmetric with violet-to-red peak ratio V/R=1. During the first half of the period (MJD58095 - MJD58360) the V/R-ratio decreased to 0.5 and the asymmetry developed simultaneously in all three lines. During the second half of the period (MJD58360 - MJD58570) the V/R-ratio increased, however with the HeI6678 line showing a markedly different behaviour than the Balmer lines. A third component with velocity >250 km/s appeared in the red side of HeI line profile. Possibly, during the first half of the period the entire disc become asymmetric and/or elliptical. The third component in HeI can be an indication for inner elliptical disc with eccentricity 0.4.