Orbital periods of cataclysmic variables identified by the SDSS*
VII. Four new eclipsing systems
Astrophysics Group, Keele University, Newcastle-under-Lyme, ST5 5BG, UK e-mail: email@example.com
2 Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
3 Isaac Newton Group of Telescopes, Apartado de Correos 321, 38700 Santa Cruz de La Palma, Spain
Accepted: 30 November 2009
We present photometry of nine cataclysmic variable stars identified by the Sloan Digital Sky Survey, aimed at measuring the orbital periods of these systems. Four of these objects show deep eclipses, from which we measure their orbital periods. The light curves of three of the eclipsing systems are also analysed using the lcurve code, and their mass ratios and orbital inclinations determined. SDSS J075059.97+141150.1 has an orbital period of min, making it a useful object with which to investigate the evolutionary processes of cataclysmic variables. SDSS J092444.48+080150.9 has a period of min and is probably magnetic. The white dwarf ingress and egress phases are very deep and short, and there is no clear evidence that this object has an accretion disc. SDSS J115207.00+404947.8 and SDSS J152419.33+220920.1 are nearly identical twins, with periods of and min and mass ratios of and , respectively. Their eclipses have well-defined white dwarf and bright spot ingress and egress features, making them excellent candidates for detailed study. All four of the orbital periods presented here are shorter than the 2–3 h period gap observed in the known population of cataclysmic variables.
Key words: dwarf novae / novae, cataclysmic variables / binaries: eclipsing / binaries: spectroscopic / white dwarfs
The reduced observational data presented in this work are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (18.104.22.168) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/510/A100 and at http://www.astro.keele.ac.uk/ jkt/.
© ESO, 2010