Spectroscopic observations of the short-period, RS CVn-type star SV Cam

Abstract

Spectroscopic observations of the eclipsing, short-period RS CVn-star SV Cam in the range Å, covering the whole orbital period are presented. The absorption profiles of the lines Hα and FeI 6678 are doubled out of the eclipses. The relative contribution of the secondary star is stronger in the FeI 6678 line than in Hα. We determined km s-1 and km s-1 by measurements of the Doppler shifts of these lines. The resulting masses of the components are: and . From the radial velocity solution and photometrically obtained relative stellar radii we determined the absolute radii of the components: and . The equatorial velocities km s-1 and km s-1 corresponding to the measured rotational broadenings of the investigated lines coincide with the velocities calculated from the obtained stellar radii. The phase behavior of both Hα and FeI 6678 profiles of the primary star shows the presence of two cool spots with maximum visibilities at phases 0.27 and 0.86. The analysis of the two lines in the middle of the primary eclipse allows us to illustrate the excess of the Hα emission of the secondary star. The parameters of the stellar components of SV Cam derived from our spectroscopy and photometry are in very good agreement. The final result of our investigation is that there are three sources of activity in SV Cam: local active regions (photospheric spots) on its primary component, enhanced chromospheric emission from the secondary star and some additional emission originating from circumstellar gas.