We present measurements of the emission core width W_0 and the wavelength separation of the K_1 dips, W_1, 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 (W_1, M_V) in these very active stars and analyse the influence of the activity level (I_K3) and the rotational broadening (Vsin i) in these correlations. We have found that for very active stars the emission widths, both W_0 and W_1, are larger than expected from previously accepted width-luminosity relations. The stars with strong emission intensities, I_K3 and large values of Vsin i seem ...
High dispersion spectra have been obtained in order to study the activity level of ten barium stars ...
Context.The main chromospheric activity indicator is the S index, which is the ratio of the flux in ...
We have studied a sample of ten RS CVn systems by means of IUE high resolution long wavelength spect...
We investigate the extent to which the Wilson-Bappu relationship holds for chromospherically active ...
We report high-resolution observations of the Ca II H and K and Balmer H_α lines in 53 chromospheric...
We report high-resolution observations of the Ca II H and K and Balmer Hα lines in 53 chromospherica...
In this work we analyze the behaviour of the excess Ca II H & K and H emissions in a sample of 73 c...
In this work we analyze the behaviour of the excess Ca II H and K and H_ ε emissions in a sample of ...
We present new spectroscopic observations in the Ca II H & K line region for a sample of 28 chromosp...
Context. The planet-star interaction is manifested in many ways. It has been found that a close-in e...
An investigation is carried out on the Wilson-Bappu effect in the Mg II k line at 2796.34 Angstrom. ...
International audienceContext. Different relationships between the Hα and Ca II chromospheric emissi...
Context. Different relationships between the Hα and Ca II chromospheric emissions have been reported...
The Wilson-Bappu effect (WBE; Wilson & Bappu, 1957) is a well-known empirical relation for cool and ...
Context. Studying chromospheric activity of contact binaries is an effective way of revealing the ma...
High dispersion spectra have been obtained in order to study the activity level of ten barium stars ...
Context.The main chromospheric activity indicator is the S index, which is the ratio of the flux in ...
We have studied a sample of ten RS CVn systems by means of IUE high resolution long wavelength spect...
We investigate the extent to which the Wilson-Bappu relationship holds for chromospherically active ...
We report high-resolution observations of the Ca II H and K and Balmer H_α lines in 53 chromospheric...
We report high-resolution observations of the Ca II H and K and Balmer Hα lines in 53 chromospherica...
In this work we analyze the behaviour of the excess Ca II H & K and H emissions in a sample of 73 c...
In this work we analyze the behaviour of the excess Ca II H and K and H_ ε emissions in a sample of ...
We present new spectroscopic observations in the Ca II H & K line region for a sample of 28 chromosp...
Context. The planet-star interaction is manifested in many ways. It has been found that a close-in e...
An investigation is carried out on the Wilson-Bappu effect in the Mg II k line at 2796.34 Angstrom. ...
International audienceContext. Different relationships between the Hα and Ca II chromospheric emissi...
Context. Different relationships between the Hα and Ca II chromospheric emissions have been reported...
The Wilson-Bappu effect (WBE; Wilson & Bappu, 1957) is a well-known empirical relation for cool and ...
Context. Studying chromospheric activity of contact binaries is an effective way of revealing the ma...
High dispersion spectra have been obtained in order to study the activity level of ten barium stars ...
Context.The main chromospheric activity indicator is the S index, which is the ratio of the flux in ...
We have studied a sample of ten RS CVn systems by means of IUE high resolution long wavelength spect...