A parameter study of the eclipsing CV in the Kepler field, KIS J192748.53+444724.5

Abstract

We present high-speed, three-colour photometry of the eclipsing dwarf nova KIS J192748.53+444724.5 (KISJ1927) which is located in the Kepler field. Our data reveal sharp features corresponding to the eclipses of the accreting white dwarf followed by the bright spot where the gas stream joins the accretion disc. We determine the system parameters via a parametrized model of the eclipse fitted to the observed light curve. We obtain a mass ratio of q = 0.570 ± 0.011 and an orbital inclination of 84.°6 ± 0.°3. The primary mass is Mw = 0.69 ± 0.07M⊙. The donor star's mass and radius are found to be Md = 0.39 ± 0.04M⊙ and Rd = 0.43 ± 0.01R⊙, respectively. From the fluxes of the white dwarf eclipse, we find a white dwarf temperature of Tw = 23000 ± 3000 K, and a photometric distance to the system of 1600 ± 200 pc, neglecting the effects of interstellar reddening. The white dwarf temperature in KISJ1927 implies the white dwarf is accreting at an average rate of Ṁ = 1.4 ± 0.8 × 10-9 M⊙ yr-1, in agreement with estimates of the secular mass loss rate from the donor. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.