EDP Sciences
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Volume 424, Number 2, September III 2004
Page(s) 647 - 655
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361:20040408

A&A 424, 647-655 (2004)
DOI: 10.1051/0004-6361:20040408

Time-resolved photometry and spectroscopy of the new deeply-eclipsing SW Sextantis star HS 0728+6738

P. Rodríguez-Gil1, B. T. Gänsicke1, H. Barwig2, H.-J. Hagen3 and D. Engels3

1  Department of Physics, University of Warwick, Coventry CV4 7AL, UK
    e-mail: Pablo.Rodriguez-Gil@warwick.ac.uk
2  Universitäts-Sternwarte, Scheinerstr. 1, 81679 München, Germany
3  Hamburger Sternwarte, Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany

(Received 8 March 2004 / Accepted 28 May 2004 )

We present time-resolved optical spectroscopy and photometry, and far-ultraviolet spectroscopy of HS 0728+6738 , a cataclysmic variable discovered in the Hamburg Quasar Survey. We show that the system is a new eclipsing member of the SW Sex class of CVs with an orbital period of 3.21 h. We derive an orbital inclination of ~ $ 85 \pm 4\degr$ from the average eclipse profile, making HS 0728+6738 the highest inclination SW Sex star known. The optical and far-ultraviolet emission lines are not or only weakly occulted during the eclipse, indicating the presence of line-emission sites either far outside the Roche lobe of the primary or, more likely, above the orbital plane of the binary. The photometric light curves exhibit fast variability with a period of ~7 min, which might be related to the spin of the white dwarf.

Key words: accretion, accretion disks -- stars: binaries: close -- stars: individual: HS 0728+6738 -- stars: novae, cataclysmic variables

SIMBAD Objects

© ESO 2004