Physical parameters and orbital period variation of a newly discovered cataclysmic variable GSC 4560-02157

• Published in: arXiv.org
• Main Authors: Zhong-tao, Han, Sheng-bang Qian, Voloshina, Irina, Metlov, Vladimir G, Li-ying, Zhu, Lin-jia, Li
• Format: Paper
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 09.05.2017
• Subjects: Boundary layers; Cataclysmic variables; Eclipses; High temperature; Low mass stars; Luminosity; Main sequence stars; Orbits; Parameters; Physical properties; Travel time; White dwarf stars
• ISSN: 2331-8422

GSC 4560-02157 is a new eclipsing cataclysmic variable with an orbital period of \(0.265359\) days. By using the published \(V-\) and \(R-\)band data together with our observations, we discovered that the \(O-C\) curve of GSC 4560-02157 may shows a cyclic variation with the period of \(3.51\) years and an amplitude of \(1.40\) min. If this variation is caused by a light travel-time effect via the existence of a third body, its mass can be derived as \(M_{3}sini'\approx91.08M_{Jup}\), it should be a low-mass star. In addition, several physical parameters were measured. The colour of the secondary star was determined as \(V-R=0.77(\pm0.03)\) which corresponds to a spectral type of K2-3. The secondary star's mass was estimated as \(M_{2}=0.73(\pm0.02)M_{\odot}\) by combing the derived \(V-R\) value around phase 0 with the assumption that it obeys the mass-luminosity relation of the main sequence stars. This mass is consistent with the mass\(-\)period relation of CV donor stars. For the white dwarf, the eclipse durations and contacts of the white dwarf yield an upper limit of the white dwarf's radius corresponding to a lower limit mass of \(M_{1}\approx0.501M_{\odot}\). The overestimated radius and previously published spectral data indicate that the boundary layer may has a very high temperature.