Ca II H and K and H_α emissions in chromospherically active binary-systems (RS Canum Venaticorum and BY Draconis)



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Fernández Figueroa, María José and Montes Gutiérrez, David and Castro Rubio, Elisa de and Cornide Castro-Piñeiro, Manuel (1994) Ca II H and K and H_α emissions in chromospherically active binary-systems (RS Canum Venaticorum and BY Draconis). Astrophysical journal supplement series, 90 (1). pp. 433-465. ISSN 0067-0049

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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.

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© 1993. The American Astronomical Society.
The INT 2.5 m on the island of La Palma and the 2.2 m telescope at Calar Alto Observatory are operated, respectively, by the Royal Greenwich Observatory at the Spanish Observatorio del Roque de los Muchachos (Instituto de Astrofísica de Canarias), and the Max Planck Institut für Astronomie at the Centro Astronómico Hispano-Alemán of Calar Alto (Almería, Spain).
We want to express our gratitude to the staff of both observatories for their help during the observations. This work has been supported by the Universidad Complutense de Madrid and the Spanish Dirección General de Investigación Científica y Técnica (DGICYT) under grant PB91-0348.

Uncontrolled Keywords:CVN system; Close binaries; Stars; Variability; Lines; Spectroscopy; Orbits
Subjects:Sciences > Physics > Astrophysics
Sciences > Physics > Astronomy
ID Code:31342
Deposited On:30 Jul 2015 10:41
Last Modified:10 Dec 2018 15:05

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