EDP Sciences
Free access
Volume 410, Number 2, November I 2003
Page(s) 649 - 661
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20031241

A&A 410, 649-661 (2003)
DOI: 10.1051/0004-6361:20031241

2MASS J0516288+260738 : Discovery of the first eclipsing late K + Brown dwarf binary system?

S. L. Schuh1, 2, G. Handler3, 4, H. Drechsel5, P. Hauschildt6, S. Dreizler1, 2, R. Medupe4, 7, C. Karl5, R. Napiwotzki5, S.-L. Kim8, B.-G. Park8, M. A. Wood9, M. Paparó10, B. Szeidl10, G. Virághalmy10, D. Zsuffa10, O. Hashimoto11, K. Kinugasa11, H. Taguchi11, E. Kambe12, E. Leibowitz13, P. Ibbetson13, Y. Lipkin13, T. Nagel1, E. Göhler1 and M. L. Pretorius14

1  Institut für Astronomie und Astrophysik, Universität Tübingen, Sand 1, 72076, Tübingen, Germany
    e-mail: schuh@astro.uni-tuebingen.de
2  Universitätssternwarte Göttingen, Geismar Landstraße 11, 37083 Göttingen, Germany
3  Institut für Astronomie, Universität Wien, Türkenschanzstraße 17, 1180 Wien, Austria
4  South African Astronomical Observatory, PO Box 9, Observatory 7935, Cape, South Africa
5  Dr.-Remeis-Sternwarte, Astronomisches Institut der Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 Bamberg, Germany
6  Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany
7  Department of Physics, University of the North-West, Private Bag X2046, Mmabatho 2735, South Africa
8  Korea Astronomy Observatory, 61-1, Whaam, Yuseong, Daejeon, 305-348, Korea
9  Department of Physics and Space Sciences and SARA Observatory, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901-6975, USA
10  Konkoly Observatory, Box 67, 1525 Budapest XII, Hungary
11  Gunma Astronomical Observatory, 6860-86 Nakayama Takayama-mura Agatsuma-gun Gunma-ken, Postal Code: 377-0702, Japan
12  Department of Earth and Ocean Sciences, National Defense Academy, Yokosuka, Kanagawa 239-8686, Japan
13  Wise Observatory, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
14  Department of Astronomy, University of Cape Town, Rondebosch 7700, South Africa

(Received 8 April 2003 / Accepted 4 August 2003 )

We report the discovery of a new eclipsing system less than one arcminute south of the pulsating DB white dwarf KUV 05134+2605 . The object could be identified with the point source 2MASS J0516288+260738 published by the Two Micron All Sky Survey. We present and discuss the first light curves as well as some additional colour and spectral information. The eclipse period of the system is 1.29 d, and, assuming this to be identical to the orbital period, the best light curve solution yields a mass ratio of m2/m1=0.11, a radius ratio of $r_2/r_1\approx 1$ and an inclination of 74°. The spectral anaylsis results in a $T_{\rm eff}=4200$ K for the primary. On this basis, we suggest that the new system probably consists of a late K + Brown dwarf (which would imply a system considerably younger than $\approx$0.01 Gyr to have $r_2/r_1\approx 1$), and outline possible future observations.

Key words: ephemerides -- stars: variables: general -- stars: binaries: eclipsing -- stars: low-mass, brown dwarfs -- stars: individual: 2MASS J0516288+260738

Offprint request: S. L. Schuh, Schuh@astro.uni.tuebingen.de

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