基于LAMOST对Kepler天区红团簇星的内部结构与演化状态的星震学研究

Long near-uninterrupted high-precision photometric timeseries observations from dedicated space missions Kepler and high-quality spectra from LAMOST have provided seismic inferences of the global and internal properties of a large number of evolved stars, including red-giant branch and red clump. Red clump with solar-like oscillation are evolved stars which have a helium burning core surrounded by a hydrogen-burning shell. The red clump is used as a new standard candlelight to measure the distance of the celestial body because of the characteristics of the large number, brightness and the small dispersion of the luminosity. As an elegant tool to study evolutionary state and internal structure of red clump, asteroseismology has been developed rapidly in recent decades. So, using asteroseismology, especially the mixed modes frequencies and parameters, we will do the research as follows: (1) Infer the age and evolutionary state of red clump, discriminate and compare the internal structure between the red-giant branch and red clump ; (2) Probe the internal structure of red clump; (3) Examine and improve the asteroseismic scaling relations in the red clump phase. So asteroseismic study of red clump will have important scientific significance for the improvement of understanding of stellar structure and evolution, study of the chemical evolution of Milky Way and other galaxies, the distance of the celestial body and dynamic evolution of star cluster.

LAMOST巡天获得的恒星光谱数据和空间卫星Kepler长周期不间断的高精度测光观测数据为揭示大量演化后期恒星（尤其是红巨星分支、红团簇星和第二红团簇群星等）的内部结构特征和星震特征参量提供机遇。具有类太阳振动的红团簇星是恒星演化到后期且内部结构复杂的的一类特殊恒星。由于数量多、明亮且光度弥散小的特点，红团簇星被采用为新的标准烛光来精确测量天体的距离。近年来，混合模式振动的观测和星震学的发展为研究红团簇星内部结构和演化状态提供了强有力的工具。据此，我们将利用星震学方法（1）确定红团簇星的年龄和演化状态，有效区分红巨星分支和红团簇星；（2）探测红团簇星的内部结构特征；（3）检验和修正红团簇星阶段星震标度关系。因此红团簇星的星震学研究将对恒星结构与演化理论、天体距离的测量和银河系结构研究有重要科学意义，也可以为星团动力学演化的研究提供帮助。

LAMOST巡天获得的恒星光谱数据和空间卫星Kepler、TESS长周期不间断的高精度测光观测数据为揭示大量演化后期恒星（尤其是红巨星分支、红团簇星和第二红团簇群星等）的内部结构特征和星震特征参量提供机遇。具有类太阳振动的红巨星是恒星演化到后期且内部结构复杂的的一类特殊恒星。由于数量多、明亮且光度弥散小的特点，红巨星被采用为新的标准烛光来精确测量天体的距离。近年来 ，混合模式振动的观测和星震学的发展为研究红团簇星内部结构和演化状态提供了强有力的工具。依托本项目资助，（1）我们分析了全天区所有TESS释放的测光观测数据，并挑选出有周期性信号和星震信号的的恒星测光数据进行求解分析其周期性和星震参量。同时利用分析结果增加和修正了变星星表的样本数量及参数。（2）我们分析了其中天区中一个扇区有星震信号并且有LAMOST光谱观测数据的恒星样本，首次获得了14颗恒星的星震参量和恒星参数。这些有星震信号的恒星均为红巨星，我们利用样本结果分析了星震标度关系，详细讨论了恒星参量之间的关系。（3）我们基于LAMOST和TESS海量数据进行变星分析，从中发现了两个极小质量比双星，使用TESS卫星和SuperWASP数据首次对小质量比密近双星TIC 393943031和TIC 89428764进行了光度分析。并对这两个极小质量比双星的周期性、演化阶段及轨道角动量进行研究讨论。