Orbital periods of cataclysmic variables identified by the SDSS. VII. Four new eclipsing systems

TL;DR

This study reports the measurement of orbital periods for nine SDSS-identified cataclysmic variables, with four showing deep eclipses, providing insights into their structure and evolution, especially for systems below the period gap.

Contribution

The paper presents four newly measured orbital periods of eclipsing cataclysmic variables, including detailed analysis of their light curves and system parameters, expanding knowledge of short-period CVs.

Findings

Four new eclipsing CVs with measured orbital periods.

Three systems analyzed for mass ratios and inclinations.

All systems have periods below the 2-3 hour period gap.

Abstract

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 134.1564 +/- 0.0008 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 131.2432 +/- 0.0014 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 97.5 +/- 0.4 and 93.6 +/- 0.5 min and mass ratios of 0.14 +/- 0.03 and 0.17 +/- 0.03, 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 hour period gap observed in the known population of cataclysmic variables.