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ULTRACAM photometry of the eclipsing cataclysmic variables XZ Eri and DV UMa

W. J. Feline·V. S. Dhillon·T. R. Marsh·C. S. Brinkworth
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Abstract

We present high-speed, three-colour photometry of the faint eclipsing cataclysmic variables XZ Eri and DV UMa. We determine the system parameters through two techniques: first, timings of the eclipse contact phases of the white dwarf and bright-spot using the derivative of the light curve; and secondly, a parameterized model of the eclipse fitted to the observed light curve by chi-squared minimisation. For both objects, we prefer the latter method, as it is less affected by photon noise and rapid flickering. For XZ Eri we obtain a mass ratio q = 0.1098 +/- 0.0017 and an orbital inclination i = 80.16 +/- 0.09 degrees. For DV UMa we derive figures of q = 0.1506 +/- 0.0009 and i = 84.24 +/- 0.07 degrees. The secondary star in XZ Eri has a very low mass Mr/Msun = 0.0842 +/- 0.0024, placing it close to the upper limit on the mass of a brown dwarf.

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W. J. Feline, V. S. Dhillon, T. R. Marsh, C. S. Brinkworth. 2004-09-08. ULTRACAM photometry of the eclipsing cataclysmic variables XZ Eri and DV UMa. https://doi.org/10.1111/j.1365-2966.2004.08302.x

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