双星与变星研究组知识库

We present the physical parameters (p, T, q, i, f) of 380 Kepler contact binary systems (hereafter called CBs). A statistical study on the CBs is carried out based on a Kepler photometric database. Our samples were selected from the Kepler Eclipsing Binary Catalogue of EW-type eclipsing binaries with periods around 0.2-1 d and amplitudes greater than 5%. The physical parameters were obtained by fitting the Kepler light curves with the Wilson-Devinney eclipsing binary modeling program. Our sample of CBs contains 160 A-type and 220 W-type CBs. The fill-out factor distribution indicated that CBs generally have shallow fill-out; the proportion of CBs with fill-out factors less than 30% is around 70%, which may be related to the formation and evolution of the CBs. The period-temperature relationship of CBs is consistent with previous studies, which is the well-known period-color relationship. The distribution between mass ratio and fill-out factor can provide some information for studying the deep, low-mass ratio contact binaries and CBs which have a large mass ratio. The mass-radius diagram shows that there is a similar linear relationship between the primary and secondary stars while the primary stars are located almost on the ZAMS line; this could be related to the internal nuclear reaction within the primary and secondary stars.