VY Scl-type cataclysmic variable SDSS J154453.60+255348.8: stellar and disc parameters

• Published in: Monthly notices of the Royal Astronomical Society 2023-03, Vol.521 (4), p.5846-5859
• Main Authors: Medina Rodriguez, A L, Zharikov, S, Kára, J, Wolf, M, Agishev, A, Khokhlov, S
• Format: Article
• Language: English
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stad881

ABSTRACT We present a new study of the eclipsing cataclysmic variable SDSS J154453.60+255348.8 to determine the object’s nature and its system parameters together with the probe of the accretion flow structure in the system. Based on analyses of new simultaneous time-resolved photometric and spectroscopic observations of SDSS J154453.60+255348.8 and using our light-curve modelling techniques and the Doppler tomography method, we found that the system contains a white dwarf with the mass of MWD = 0.62(7) M⊙ and an evolved red dwarf as a secondary. The system inclination is close to 90° and the mass ratio is q = 0.49(2). The secondary has an effective temperature T2 = 3400(40) K and a radius about 1.35(15) times larger than a zero-age main-sequence star with similar mass. From observation of the system in high- and low-brightness states, we conclude that SDSS J154453.60+255348.8 is a long-orbital period VY Scl-type system. The accretion disc in the high state is about two times less than the truncation radius, and is completely missing during the low state of the system.