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A Survey of IUE Spectra of the Active Binary System UX Arietis

Published online by Cambridge University Press:  02 January 2013

Fehmi Ekmekçi
Fehmi Ekmekçi
Affiliation:
Ankara University, Faculty of Science, Department of Astronomy and Space Sciences, 06100 Tandoğan, Ankara, Turkey. Email: [email protected]
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Abstract

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To investigate the ultraviolet (UV) activity of the bright, non-eclipsing, double-lined spectroscopic binary system UX Ari, IUE spectra (194 images) were taken from the IUE archive. The spectra, obtained during the period 1978–1996, show emission lines originating in the chromosphere and transition region. The long-wavelength low dispersion spectra were examined for ultraviolet excess by comparing the UV continuum level of UX Ari with the levels of k Cet and η Cep in the spectral range 2100–3200 Å. The individual Mgiih and k emission-line fluxes of component stars show that the contributions to the activity of the system for G5 V and K0 IV are about 20% and 80%, respectively. Apart from the flare event observed on 1979 Jan 1, there are some flux enhancements in the years 1987, 1991 and 1994 which may suggest existence of a periodicity of about 7–9 years. Examination of the ultraviolet excess in the system showed that there is some UV excess in UX Ari, which varies from 1% up to 24% with the exception of two images which showed no UV excess. The results revealed that there was an agreement on the source of emission regions which could be attributed to magnetic activity. The contribution of G5 V and K0 IV components to the Mgii activity of the system suggests a need to take into consideration the spot distribution not only on the surface of the K0 IV but also on the surface of the G5 V component of UX Ari.

Keywords

binaries: spectroscopicstars: activitystars: chromospheresstars: individual (UX Ari)
Type
Research Article
Information
Publications of the Astronomical Society of Australia , Volume 27 , Issue 1 , 2010 , pp. 1 - 14
Copyright
Copyright © Astronomical Society of Australia 2010

References

Aarum Ulvås, V. & Engvold, O., 2003, A&A, 402, 1043Google Scholar
Athay, R. G., 1965, ApJ, 142, 755CrossRefGoogle Scholar
Bevington, P. R., 1969, Data Reduction and Error Analysis for The Physical Sciences (New York: McGraw-Hill), 237Google Scholar
Blackwell, D. E. & Lynas-Gray, A. E., 1994, A&A, 282, 899Google Scholar
Carlos, R. C. & Popper, D. M., 1971, PASP, 83, 504CrossRefGoogle Scholar
Duemmler, R. & Aarum, V., 2001, A&A, 370, 974Google Scholar
Ekmekçi, F., 1993, PhD Thesis, Ankara University Graduate School of Natural and Applied SciencesGoogle Scholar
Gray, D. F., 1992, The Observations and Analysis of Stellar Photospheres (Second Edition; New York: Cambridge University Press), 340Google Scholar
Gu, S.-h., Tan, H.-s., Shan, H.-g. & Zhang, F.-h., 2002, A&A, 388, 889Google Scholar
Huenemoerder, D. P., Buzasi, D. L. & Ramsey, L. W., 1989, AJ, 98, 1398CrossRefGoogle Scholar
Jordan, C., 1975, MNRAS, 170, 429CrossRefGoogle Scholar
Kohl, J. L., 1977, ApJ, 211, 958CrossRefGoogle Scholar
Lang, K. R. & Willson, R. F., 1988, ApJ, 328, 610CrossRefGoogle Scholar
Montes, D., Fernández-Figueroa, M. J., De Castro, E. & Cornide, M., 1995a, A&AS, 109, 135Google Scholar
Montes, D., Fernández-Figueroa, M. J., De Castro, E. & Cornide, M., 1995b, A&A, 294, 165Google Scholar
Mutel, R. L., Morris, D. H., Doiron, D. J. & Lestrade, J. F., 1987, AJ, 93, 1220CrossRefGoogle Scholar
Nichols, J. S. & Linsky, J. L., 1996, AJ, 111, 517CrossRefGoogle Scholar
Perryman, M. A. C. et al. , 1997, A&A, 323L, 49Google Scholar
Raveendran, A. V. & Mohin, S., 1995, A&A, 301, 788Google Scholar
Rego, M., Gonzalez-Riestra, R. & Fernández-Figueroa, M. J., 1983, A&A, 119, 227Google Scholar
Rhombs, C. G. & Fix, J. D., 1977, ApJ, 216, 503CrossRefGoogle Scholar
Rodonó, M., 1980, MmSAI, 51, 623Google Scholar
Simon, T., Linsky, J. L. & Schiffer, F. H., 1980, ApJ, 239, 911CrossRefGoogle Scholar
Soubiran, C., Bienaymé, O., Mishenina, T. V. & Kovtyukh, V. V., 2008, A&A, 480, 91Google Scholar
Strassmeier, K. G. et al. , 1988, A&AS, 72, 291Google Scholar
Strassmeir, K. G., Hall, D. S., Fekel, F. C. & Scheck, M., 1993, A&AS, 100, 173Google Scholar
Vogt, S. S. & Hatzes, A. P., 1991, IAUC, 130, 297Google Scholar
Zirin, H., 1976, ApJ, 208, 414CrossRefGoogle Scholar