ИСТИНА

We report the results of a photometric and spectroscopic monitoring of the B[e] object CI Cam since its multiwavelength outburst in 1998. We found a system component, which radiates in the He II 4686 A emission line, on an elliptical orbit around an early-B type star with an orbital period of 19.407+/–0.004 days and an eccentricity of 0.43–0.49. The amplitude of the He II radial velocity variations is ~380 km/s. The line intensity gradually increases with time. A slow secular change of the radial velocity of iron emission lines and a forbidden nitrogen line has been detected at high resolution. This phenomenon can be due to the presence of a third component on an eccentric orbit or to precession of the rotational axis of the B-type star and its polar outflows. The B-type star, turned out to be a multiperiodic pulsating variable with periods of 0.5223, 0.41539, and 0.26630 days. However, since 2012 it pulsates in a single mode with a range of periods between 0.403 and 0.408 days depending on the star’s luminosity. The pulsational data constrain the spectral type of the B-star at B0-B2 III, the distance to the system at 2.5–4.5 kpc, and the absolute visual magnitude at –3.7 – –4.9 mag. The previously suggested classification of the object as a B[e] supergiant is rejected because of the observed pulsations periods.