LAMOST特殊EW型双星的观测和研究

我国的LAMOST是国际上获取光谱率最高的大视场巡天望远镜。到目前为止已获得了一万多颗EW型双星的恒星大气参量，为研究相接双星及相关天体的物理特性奠定了坚实基础。相接双星是两子星均充满各自的洛希瓣且具有对流公共包层的相互作用双星系统，其轨道周期（P）和表面有效温度（T）间存在良好的线性递增关系。然而LAMOST却发现一些明显不符合P-T关系的“特殊相接双星”样本，它们的表面有效温度相对于周期明显偏高。对这些样本星进行系统的观测和深入研究对于了解相接双星的形成和演化，搜寻特殊脉动变星等具有重要意义。本项目将对这些不满足P-T关系的特殊变星进行后续观测，结合已有的巡天数据和LAMOST恒星大气参量对它们进行详细的甄别、分类和分析研究，发现特殊的相接双星系统，搜寻被错划分的特殊变星等，求解它们的基本物理参量，探讨它们的物理性质、结构特征和演化状态，推动相接双星和物理变星研究领域的发展。

LAMOST in China is a survey telescope with a large field of view and the highest spectrum acquiring rate in the world. Up to now, the atmospheric parameters of more than 10000 EW-type binary stars have been obtained, which has laid a solid foundation for the study of the physical properties of the contact binary stars and related stars. The contact binary system is an interactive system with both components filling their Roche lobes and a common convective envelope. There is a good linear increasing relationship between the orbital period (P) and the surface effective temperature (T). However, it is found by LAMOST that some “special contact binary” samples do not conform to the P-T relationship, and their surface effective temperature is too high compared with a short period. The systematic observation and comprehensive study of these sample stars are of great significance to understand the formation and evolution of the contact binary stars and to search for special pulsating stars. At here, we will observe these special variable stars that are outside this trend. Combining the existing sky survey data and the atmospheric parameters given by LAMOST, they will be screened, classified and analyzed, to find out special contact binary systems and to search for the special variable stars that are misclassified. Their basic physical parameters will be solved and their physical properties, structural characteristics, and evolutionary state will be discussed to promote the development of the contact binary stars and the physical variable stars.