A Comprehensive Study of the Long-Period Cataclysmic Variable V630 Cassiopeiae

Abstract: We present a comprehensive review of V630 Cassiopeiae, which is a very long-period cataclysmic variable. Based on new observations combining spectroscopy and high-resolution photometry provided by TESS and precise distance data from GAIA, we confirm and extend previously described characteristics. The light curves show differential behaviors between different epochs, attributed to changes in the disk's brightness distribution, likely due to non-axial structures such as precessing eccentric disks. The spectroscopy reveals complex Ha line profiles, with dual components and an emission distribution that suggests a large, asymmetric, and possibly precessing disk, rather than a classic shock structure in the matter-flow impact region. Doppler tomography indicates that the emission originates at the periphery of the disk, distributed in an asymmetric pattern rather than a compact point, complicating the interpretation of radial velocities and limiting their use for accurately determining masses. Through photometric and spectroscopic analysis, we established a donor mass estimate with an approximate value of 0.38 Ms at the adopted distance of 2409 pc, with significant uncertainty related to distance and other systematic factors. Finally, using the parameters of V630 Cas, binary evolution simulations were conducted with MESA incorporating CARB magnetic braking prescription to identify an evolutionary sequence that explains its properties.