CA-II H AND K AND H-ALPHA EMISSIONS IN CHROMOSPHERICALLY ACTIVE BINARY-SYSTEMS (RS-CANUM-VENATICORUM AND BY-DRACONIS)

We report high-resolution observations of the Ca II H and K and Balmer Halpha lines in 53 chromospherically active binary systems including the RS Canum Venaticorum binaries (RS CVn) and BY Draconis (BY Dra) cl asses. The rotational periods of the sample cover a range from 0.8 to 83.2 days. H and K emission-line surface fluxes have been calculated f or all the stars in the sample. In spectra where the Hepsilon line app ears in emission, absolute surface fluxes were also determined. The Ca II line profiles corresponding to different seasons and orbital phase s are analyzed in order to determine the contribution of each componen t and to study the chromospheric activity variations. We have measured the Halpha equivalent width of the program stars and the Halpha core emission was determined by subtraction of the equivalent width of a pr esumably inactive star of the same spectral type and luminosity class. Three different types of Halpha line profiles have been found: strong emission line, weak emission line with strong superposed absorption p rofile, and filled-in absorption line profile.