摘要
We present new photometry for two contact binaries,Y Sex and V1363 Ori,which were observed by three small telescopes in China.By using the W-D method,the absolute parameters are updated from new BVR light curves and previous radial velocity curves.Results identify that two binaries are deep,lowmass ratio(DLMR)overcontact binaries with q≤0.25 and f≥50%.From the temperature-luminosity diagram,the primary components are slightly evolved main-sequence stars,whose evolutionary ages are~2.51 Gyr for Y Sex and~3.56 Gyr for V 1363 Ori,respectively.From the(O-C)curves,it is found that the orbital periods may be undergoing secular increase with cyclic variations,which may be interpreted either by magnetic activity cycles or by the light-time orbit effect.With period increasing,this kind of DLMR overcontact binaries,such as Y Sex and V1363 Ori,will evolve into the rapid-rotating single stars.
基金
the National Natural Science Foundation of China(No.11873003)
the Natural Science Research Key Program of Anhui Provincial Department of Education(No.kj2019A0954)
the Outstanding Young Talents Program of Anhui Provincial Department of Education(gxgnfx2019084)
the Open Project Program of the Key Laboratory of Optical Astronomy of NAOC。