Orbital periods of cataclysmic variables identified by the SDSS

Free access article

Issue		A&A Volume 507, Number 2, November IV 2009


Page(s)		929 - 937
Section		Stellar structure and evolution
DOI		http://dx.doi.org/10.1051/0004-6361/200912885
Published online		15 September 2009

A&A 507, 929-937 (2009)
DOI: 10.1051/0004-6361/200912885

VI. The 4.5-h period eclipsing system SDSS J100658.40+233724.4

J. Southworth¹, R. D. G. Hickman¹, T. R. Marsh¹, A. Rebassa-Mansergas^{1, 2}, B. T. Gänsicke¹, C. M. Copperwheat¹, and P. Rodríguez-Gil^{3, 4}

¹ Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
e-mail: jkt@astro.keele.ac.uk
² Departamento de Física y Astronomía, Universidad de Valparaíso, Avenida Gran Bretana 1111, Valparaíso, Chile
³ Isaac Newton Group of Telescopes, Apdo. de Correos 321, 38700 Santa Cruz de La Palma, Spain
⁴ Instituto de Astrofísica de Canarias, vía Líctea, s/n, La Laguna, 38205 Tenerife, Spain

Received 14 July 2009 / Accepted 13 September 2009

Abstract
We present time-resolved spectroscopy and photometry of SDSS J100658.40+233724.4, which we have discovered to be an eclipsing cataclysmic variable with an orbital period of 0.18591324 days (267.71507 min). The observed velocity amplitude of the secondary star is $276 \pm 7$ km s^-1, which an irradiation correction reduces to $258 \pm 12$ km s^-1. Doppler tomography of emission lines from the infrared calcium triplet supports this measurement. We have modelled the light curve using the LCURVE code and Markov Chain Monte Carlo simulations, finding a mass ratio of $0.51 \pm 0.08$ . From the velocity amplitude and the light curve analysis we find the mass of the white dwarf to be $0.78 \pm 0.12$ ${{M}_\odot}$ and the masses and radii of the secondary star to be $0.40 \pm 0.10$ ${{M}_\odot}$ and $0.466 \pm 0.036$ ${{R}_\odot}$ , respectively. The secondary component is less dense than a normal main sequence star but its properties are in good agreement with the expected values for a CV of this orbital period. By modelling the spectral energy distribution of the system we find a distance of $676 \pm 40$ pc and estimate a white dwarf effective temperature of $16\,500 \pm 2000$ K.

Key words: stars: novae, cataclysmic variables -- stars: dwarf novae -- stars: binaries: eclipsing -- stars: binaries: spectroscopic -- stars: white dwarfs -- stars: individual: SDSS J100658.40+233724

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.