Astronomy and Astrophysics, volume 285, 609-620 (1994/5-2)
The Wilson-Bappu effect and other Ca II H and K line parameters relationships in chromospherically active binaries.
MONTES D., FERNANDEZ-FIGUEROA M.J., DE CASTRO E. and CORNIDE M.
Abstract (from CDS):
We present measurements of the emission core width W0 and the wavelength separation of the K1 dips, W1, of the Ca II H and K emission lines observed on high-dispersion spectra of 28 chromospherically active binary systems (RS CVn and BY Dra stars) and 18 single active stars. We test the width-luminosity correlations (the Wilson-Bappu (WB) effect, and (W1, MV)) in these very active stars and analyse the influence of the activity level (IK3) and the rotational broadening (Vsin i) in these correlations. We have found that for very active stars the emission widths, both W0 and W1, are larger than expected from previously accepted width-luminosity relations. The stars with strong emission intensities, IK3, and large values of Vsin i seem to present larger values of W0 than resulted from WB relation, the effect of the rotational velocity being the most remarkable. On the contrary, W1 is strongly influenced by IK3 but the effect of the rotational broadening is lesser. We also analyse the behaviour of the Ca II H and K line parameters in these very active stars in relation with less active stars and we found that the increase of W1 and IK1 with IK3 presents a flattening for the most active stars which is different for each value of W0. Finally we also find a Hε width-luminosity correlation in the stars of the sample in which this emission line is present.