Publication: Lithium abundance and activity in a sample of RS Canum Venaticorum and BY Draconis stars
Loading...
Full text at PDC
Publication Date
1993-07
Authors
Barrado y Navascués, D.
Castro Rubio, Elisa de
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
EDP Sciencies
Citations
Exportar
Abstract
Observations of the Li i doublet at 6707.8 angstrom for a sample of active binary systems RS CVn and By Dra have been carried out at the Calar Alto Observatory with the 2.2 m telescope. In addition, some single stars with different chromospheric activity levels have also been observed mainly for comparison purposes. Gaussian fits have been performed in order to separate the Fe I line at 6707.4 angstrom which is usually blended with the Li I doublet. Once the fit was achieved, the equivalent width was measured for each separated line. The contributions due to the continuum from both components have been taken into account to correct the equivalent width measurements. A curve-of-growth method has been used to derive lithium abundances. We have obtained a Li excess in the binary systems, in particular the K type stars. A correlation of the Li abundance with the activity levels is confirmed, as it was found by other authors, but RS CVn and BY Dra systems are 0.5 dex more active than single stars for the same Li abundance.
Description
© European Southern Observatory.
© 1993 EDP Sciencies.
The authors acknowlege valuable discussion with and suggestion from Roberto Pallavicini. The Calar Alto Observatory is operated jointly by the Max-Planck-Institut für Astronomie (Heidelberg) and the Spanish Comisión Nacional de Astronomía. We thank the Calar Alto staff for their help during the observations. This work has been supported in part by the Universidad Complutense de Madrid.
UCM subjects
Unesco subjects
Keywords
Citation
Anderson, J., Gustafsson, B., and Lambert, D. L., 1984, A&A 136, 65
Baglin, A., Morel, P., and Schatzman, E., 1985, A&A 149, 309
Balachandran, S., 1990, ApJ 354, 310
Basri, G., Martín, E. L.,Bertout, C., 1991, A&A 252, 625
Bell, R. A., Eriksson , K., Gustafsson, B., Nordlund, A., 1976, A&AS 23, 37
Boesgaard, A. M., and Tripicco, M., 1986a, ApJS 302, L49
Boesgaard, A. M., and Tripicco, M . J ., 1986b, ApJ 303, 724
Boesgaard, A. M., and Tripicco, M. J., 1987, ApJ 313, 389
Boesgaard, A. M ., 1991, ApJ 370, L95
Bohm-Vitense , E., 1981, ARA&A 19, 295
Charbonneau, P., and Michaud, G., 1990, ApJ 352, 681
Charbonnel, C. Vaclair, S., and Zahn, J. P., 1992, A&A 255, 191
Cayrel, R., Cayrel de Stroebel, G., Campbell, B., Däppen, W., 1984, ApJ 283, 205
Duncan , D. K., 1981, Apj 248, 651
Fernández Figueroa, M.J ., Montes, D., De Castro, E., Comide, M., 1992, (submitted to ApJS)
Fekel , F. C., Moffett, T. J., Henry, G. W., 1986, ApJS 60, 551.
García López, R.J., and Spruit, H.C., 1991, ApJ 377, 268
Giménez, A., Reglero, V., de Castro, E., Fernández Figueroa, M.J., 1991, A&A 248, 563
Gustafsson, B., Bell, R. A., Eriksson, K., Nordlund , A., 1975, A&A 42, 407
Hall, D.S., Henry, G., W., 1990, Active close binaries, Kluwer Academic Publishers, 287
Hobbs, L. M., lben, L., Pilachowski , C., 1989, ApJ 347, 817
Hoffleit, D., Jaschek, C., 1982, The Bright Star Catalogue, Yale University Observatory.
Lemoine, M., Ferlet, R., Emerich, C., Vidal-Madjar, A., Dennefeld , M., 1992, Messenger 67, 40.
Michaud, G., Charbonneau, P., 1991, Space Sci. Rev. 57, 1 Montesinos, B., 1986, Thesis.
Moss. D , 1986, Physics Reports 140(1),1.
Noyes, R.W., Hartmann , L., Baliunas, S., Duncan, D., and Vaugham , A.H., 1984, ApJ 279, 763
Pallavicini, R., Cerruti Sola, M., and Duncan, D. K., 1987, A&A 174, 116
Pallavicini, R., Randich, S., and Giampapa, M.S., 1992, A&A 253, 185
Pinsonneault, M.H., Kawaler, S.D., Sofia, S., Demarque, P., 1989, ApJ 338, 424
Pinsonneault, M.H., Kawaler, S.D., Demarque, P., 1990, ApJS 74, 501
Popper, D.M., 1980, ARA&A, 18, 115
Randich. S., Pallavicini, R., 1991, Mem. Soc. Astron. Ital. 62, 75
Rebolo, R., Molaro, P., Beckman, J. E., 1988, A&A 192, 192 Rebolo, R., Beckman, J . E., 1988, A&A 201, 267
Rebolo, R., 1989, Astrophysics and Space Sci. 157, 47
Reglero, V., Fernández Figueroa, M. J., Giménez, A., De Castro, E., Fabregat, J., Comide. M., Armentia, J . E., 1991, A&AS 88, 545.
Rutten, R.G.M., 1987, A&A 177, 131
Simon, T., Drake, S.A., 1989, ApJ 346, 303
Soderblom, D. R., Oey, M . S., Johnson, D. R. H., 1990, AJ 99, 595
Soderblom, D., R., 1991, Mem. Soc. Astron. Ital. 62, 43
Spite, M., Maillard, J. P., and Spite, F., 1984, A&A 141, 56.
Strasmeier, K.G., Hall, D.S., Zeilik, M., Nelson, E., Eker, Z., and Fekel, F.C., 1988, A&AS 72, 291
Strassmeier, K.G., Fekel, ,F.C., Bopp, B.W., Demsey, R.C., Henry, G.W., 1990, ApJS 72, 191