Ca II H and K and H_α 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 H_α lines in 53 chromospherically active binary systems including the RS Canum Venaticorum binaries (RS CVn) and BY Draconis (BY Dra) classes. The rotational periods of the sample cover a range from 0.8 to 83.2 days. H and K emis...

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Detalhes bibliográficos
Autores: Fernández Figueroa, María José, Montes Gutiérrez, David, Castro Rubio, Elisa De, Cornide Castro-Piñeiro, Manuel
Formato: artículo
Fecha de publicación:1994
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/59663
Acesso em linha:https://hdl.handle.net/20.500.14352/59663
Access Level:acceso abierto
Palavra-chave:52
CVN system
Close binaries
Stars
Variability
Lines
Spectroscopy
Orbits
Astrofísica
Astronomía (Física)
Descrição
Resumo:We report high-resolution observations of the Ca II H and K and Balmer H_α lines in 53 chromospherically active binary systems including the RS Canum Venaticorum binaries (RS CVn) and BY Draconis (BY Dra) classes. 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 for all the stars in the sample. In spectra where the H_ε line appears in emission, absolute surface fluxes were also determined. The Ca II line profiles corresponding to different seasons and orbital phases are analyzed in order to determine the contribution of each component and to study the chromospheric activity variations. We have measured the H_α equivalent width of the program stars and the H_α core emission was determined by subtraction of the equivalent width of a presumably inactive star of the same spectral type and luminosity class. Three different types of H_α line profiles have been found: strong emission line, weak emission line with strong superposed absorption profile, and filled-in absorption line profile.