D. Montes et al., APPLICATION OF THE SPECTRAL SUBTRACTION TECHNIQUE TO THE CA-II-H-AND-K AND H-EPSILON LINES IN A SAMPLE OF CHROMOSPHERICALLY ACTIVE BINARIES, Astronomy & Astrophysics. Supplement series, 114(2), 1995, pp. 287-323
We present new spectroscopic observations in the Ca II H & K line regi
on for a sample of 28 chromospherically active binary systems (RS CVn
and BY Dra classes), with different activity levels. By using the spec
tral subtraction technique (subtraction of a synthesized stellar spect
rum constructed from reference stars of similar spectral type and lumi
nosity class) we obtain the active-chromosphere contribution to the Ca
II H & K lines and to the HE line when it is present. We have compare
d the emission equivalent widths obtained with this technique with tho
se obtained by reconstruction of the absorption line profile below the
emission peak(s). The emissions arising from each individual star wer
e obtained when it was possible to deblend the contribution of both co
mponents. The Ca II line profiles corresponding to different seasons a
nd orbital phases are analysed in order to determine the contribution
of each component and to study the chromospheric activity variations.