The quiescent periodic photometric modulations of two low-inclination
cataclysmic variables observed in Kepler K2 Campaigns 0 and 1, KZ Gem and TW
Vir, are investigated. A phase-correcting method was successfully used to
detect the orbital modulations of KZ Gem and TW Vir and improve their orbital
periods. The light curve morphologies of both CVs were further analyzed by
defining flux ratios and creating colormaps. KZ Gem shows ellipsoidal
modulations with an orbital period of 0.22242(1) day, twice the period listed
in the updated RK catalogue (Edition 7.24). With this newly determined period,
KZ Gem is no longer a CV in the period gap, but a long-period CV. A part of the
quiescent light curve of TW Vir that had the highest stability was used to
deduce its improved orbital period of 0.182682(3) day. The flat patterns shown
in the colormaps of the flux ratios for KZ Gem demonstrate the stability of
their orbital modulations, while TW Vir show variable orbital modulations
during the K2 datasets. In TW Vir, the single versus double-peaked nature of
the quiescent orbital variations before and after superoutburst may be related
to the effect of the superoutburst on the accretion disk.Comment: 10 pages, 12 figures, accepted by A&
