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DE Canum Venaticorum : a bright, eclipsing red dwarf–white dwarf binary

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Besselaar, E. J. M. van den, Greimel, R., Morales-Rueda, L., Nelemans, G., Thorstensen, John Robert, Marsh, T. R., Dhillon, V. S., Robb, R. M. (Russell M.), Balam, D. D., Guenther, Eike W., Kemp, J. (Jonathan), Augusteijn, T. and Groot, P. J. (Paul J.). (2007) DE Canum Venaticorum : a bright, eclipsing red dwarf–white dwarf binary. Astronomy & Astrophysics, Vol.466 (No.3). pp. 1031-1041. ISSN 0004-6361

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Official URL: http://dx.doi.org/10.1051/0004-6361:20066246

Abstract

Context. Close white dwarf–red dwarf binaries must have gone through a common-envelope phase during their evolution. DE CVn is a detached white dwarf–red dwarf binary with a relatively short (∼8.7 h) orbital period. Its brightness and the presence of eclipses makes this system ideal for a more detailed study. Aims. From a study of photometric and spectroscopic observations of DE CVn we derive the system parameters that we discuss in the framework of common-envelope evolution. Methods. Photometric observations of the eclipses are used to determine an accurate ephemeris. From a model fit to an average lowresolution spectrum of DE CVn, we constrain the temperature of the white dwarf and the spectral type of the red dwarf. The eclipse light curve is analysed and combined with the radial velocity curve of the red dwarf determined from time-resolved spectroscopy to derive constraints on the inclination and the masses of the components in the system. Results. The derived ephemeris is HJDmin = 2 452 784.5533(1) + 0.3641394(2) × E. The red dwarf in DE CVn has a spectral type of M3V and the white dwarf has an effective temperature of 8 000 K. The inclination of the system is 86+3◦ −2 and the mass and radius of the red dwarf are 0.41 ± 0.06 M and 0.37+0.06 −0.007 R, respectively, and the mass and radius of the white dwarf are 0.51+0.06 −0.02 M and 0.0136+0.0008 −0.0002 R, respectively. Conclusions. We found that the white dwarf has a hydrogen-rich atmosphere (DA-type). Given that DE CVn has experienced a common-envelope phase, we can reconstruct its evolution and we find that the progenitor of the white dwarf was a relatively lowmass star (M ≤ 1.6 M). The current age of this system is 3.3−7.3 × 109 years, while it will take longer than the Hubble time for DE CVn to evolve into a semi-detached system.

Item Type:	Journal Article
Subjects:	Q Science > QB Astronomy
Divisions:	Faculty of Science > Physics
Library of Congress Subject Headings (LCSH):	Eclipsing binaries, Double stars -- Evolution, Red dwarf stars, White dwarf stars
Journal or Publication Title:	Astronomy & Astrophysics
Publisher:	EDP Sciences
ISSN:	0004-6361
Date:	May 2007
Volume:	Vol.466
Number:	No.3
Page Range:	pp. 1031-1041
Identification Number:	10.1051/0004-6361:20066246
Status:	Peer Reviewed
Access rights to Published version:	Open Access
Funder:	Nederlandse Organisatie voor Wetenschappelijk Onderzoek [Netherlands Organisation for Scientific Research] (NWO), National Science Foundation (U.S.) (NSF), Particle Physics and Astronomy Research Council (Great Britain) (PPARC), Instituto de Astrofísica de Canarias
Grant number:	639.042.201 (NWO), 638.041.405 (NWO), AST-9987334 (NSF), AST-0307413 (NSF), PP/D002370/1 (PPARC), PPA/G/S/2003/00058 (PPARC)
References:	Bergeron, P.,Wesemael, F., & Fontaine, G. 1991, ApJ, 367, 253 Bergeron, P., Saumon, D., & Wesemael, F. 1995, ApJ, 443, 764 Brinkworth, C. S., Marsh, T. R., Dhillon, V. S., & Knigge, C. 2006, MNRAS, 365, 287 Bruch, A. 1999, AJ, 117, 3031 de Jager, C., Heise, J., Avgoloupis, S., et al. 1986, A&A, 156, 95 de Jager, C., Heise, J., van Genderen, A. M., et al. 1989, A&A, 211, 157 de Kool, M. 1992, A&A, 261, 188 de Kool, M., van den Heuvel, E. P. J., & Pylyser, E. 1987, A&A, 183, 47 Dehnen, W., & Binney, J. J. 1998, MNRAS, 298, 387 Dewi, J. D. M., & Tauris, T. M. 2000, A&A, 360, 1043 Dhillon, V., & Marsh, T. 2001, New Astron. Rev., 45, 91 Eggleton, P. P. 1983, ApJ, 268, 368 Fuhrmann, K. 2004, Astronomische Nachrichten, 325, 3 Green, R. F., Schmidt, M., & Liebert, J. 1986, ApJS, 61, 305 Haefner, R. 1989, A&A, 213, L15 Holmes, S., & Samus, N. 2001, J. Am. Association of Variable Star Observers (JAAVSO), 29, 148 Hurley, J. R., Pols, O. R., & Tout, C. A. 2000, MNRAS, 315, 543 Johnson, D. R. H., & Soderblom, D. R. 1987, AJ, 93, 864 King, A. R. 1988, QJRAS, 29, 1 Kirkpatrick, J. D., Henry, T. J., & McCarthy, D. W. 1991, ApJS, 77, 417 Marsh, T. R. 2000, New Astron. Rev. , 44, 119 Maxted, P. F. L., Marsh, T. R., Morales-Rueda, L., et al. 2004, MNRAS, 355, 1143 Monet, D. G., Levine, S. E., Canzian, B., et al. 2003, AJ, 125, 984 Morales-Rueda, L., Marsh, T. R., Maxted, P. F. L., et al. 2005, MNRAS, 359, 648 Nelemans, G., & Tout, C. A. 2005, MNRAS, 356, 753 O’Donoghue, D., Koen, C., Kilkenny, D., et al. 2003, MNRAS, 345, 506 Paczy´nski, B. 1976, in Structure and Evolution of Close Binary Systems, IAU Symp., 73, 75 Panei, J. A., Althaus, L. G., & Benvenuto, O. G. 2000, A&A, 353, 970 Pickles, A. J. 1998, PASP, 110, 863 Reid, I. N., Hawley, S. L., & Gizis, J. E. 1995, AJ, 110, 1838 Robb, R. M., & Greimel, R. 1997, Information Bulletin on Variable Stars, 4486, 1 Schreiber, M. R., & Gänsicke, B. T. 2003, A&A, 406, 305 Smith, J. A., Tucker, D. L., Kent, S., et al. 2002, AJ, 123, 2121 Taam, R. E., & Sandquist, E. L. 2000, ARA&A, 38, 113 Tas, G., Sipahi, E., Dal, H. A., et al. 2004, Information Bulletin on Variable Stars, 5548, 1 Verbunt, F., & Rappaport, S. 1988, ApJ, 332, 193 Verbunt, F., & Zwaan, C. 1981, A&A, 100, L7 Voges, W., Aschenbach, B., Boller, T., et al. 1999, A&A, 349, 389 Wesemael, F., Greenstein, J. L., Liebert, J., et al. 1993, PASP, 105, 761 Wood, M. A. 1995, in LNP Vol. 443,White Dwarfs, ed. D. Koester & K.Werner, 41
URI:	http://wrap.warwick.ac.uk/id/eprint/3469