On Periodic Variations in the Spectrum of the BOe Star X Persei Associated with the X-Ray Source 3u 0352+30
The bright BOe star X Persei has been observed for over fifthy years, both as an emission line object and as a variable star. The discovery that the star is situated very close to the position of a weak X-ray source renewed the interest on the star and up to the present it has been under close scrutiny by a number of observers. In the course of an investigation of all available spectroscopic data, Hutchings (1974) found evidence for a long period absorption velocity variation, that may indicate
... , that may indicate the presence of a massive orbiting compa nion. A period of about 581 day was found by Hutchings for the broad Balmer absorption. Then the 22-hr and 13,9 min periodicities were discovered in the X-ray range between 0.6 and 7.5 keV. However the search for the 22.4 hr perio dicity in the radial velocity data made by Hutchings (1977) was not suc cessful . At the Crimean Observatory the spectroscopic observation, of X Persei has been started in November 1974. The spectrograms with dispersions 30 and 36 A/mm in the regions Ha and at A A 4950-3650 A were obtained from November 1974 to December 1980 ; about 2000 days were covered by us observations. The search for the evidence for the periodicities of 581 day and for the 22 hr in the variations of the radial velocity was made by us using the homogeneous observations from November 1974 to March 1978. On figure 1 can see that the broad Balmer absorption shows the period of 581 day in the variations V r as found by Hutchings, but the velocity amplitude proved to be about 50 km/sec. Hel lines revealed variations of V r with a velocity amplitude of -22 km/sec and a large scatter in the measurements ; furthermore the phase 189 M. Jaschek and H.-G. Groth (eds.), Be Stars, 189-194.