2009A&A...507..929S

We present time-resolved spectroscopy and photometry of SDSSJ100658.40+233724.4, which we have discovered to be an eclipsing cataclysmic variable with an orbital period of 0.18591324 days (267.71507min). The observed velocity amplitude of the secondary star is 276±7km/s, which an irradiation correction reduces to 258±12km/s. 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±0.08. From the velocity amplitude and the light curve analysis we find the mass of the white dwarf to be 0.78±0.12M_☉ and the masses and radii of the secondary star to be 0.40±0.10M_☉ and 0.466±0.036R_☉, 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±40pc and estimate a white dwarf effective temperature of 16500 ±2000K.