Towards stellar seismology of massive pulsators with the CoRoT and Kepler satellites

星震学是研究恒星振荡的科学，是探索恒星内部结构并显著提高我们对恒星演化的理解的唯一途径。通过光和光谱的变化测量恒星的脉动频率和其他振荡模式参数，可以限制恒星内部的物理性质。对比太阳质量更大的恒星进行星震研究尤其重要，因为这些恒星具有不同的内部结构，是最终将用重金属丰富其环境的天体的祖先，因此决定了银河系的演化。大质量恒星中的脉动模选择机制尚未完全了解，必须依赖于自转和对流之间的非线性效应的组合。只有对大量脉动的恒星进行系统的星震研究，从而对恒星的内部性质施加限制，才能解决天体物理学中的这个悬而未决的问题。由于最近发射的CoRoT和开普勒太空任务为数千颗脉动恒星提供了出色的光度学时间序列，因此有可能首次调查每个脉动类足够大的样本的脉动行为。在这个项目中，我们将研究尚未被很好理解的γDOR恒星(光谱类型A-F，M=1.2m-2.5m⊙)中的CoRoT和开普勒脉动子。我们将对目标建模，约束脉动机制，并得出这类脉动源的第一个可靠的地震描述。

Asteroseismology, the study of stellar oscillations, is the only way to probe the internal structure of stars and significantly improve our understanding of stellar evolution. By measuring stellar pulsation frequencies and other oscillation mode parameters through light and spectral variations, one can constrain the physical properties of stellar interiors. Asteroseismic studies of more massive stars than the Sun are in particular important as these stars have a different internal structure and are the progenitors of objects that will finally enrich their environment with heavy metals, and hence rule galactic evolution. The pulsation mode selection mechanism in massive stars is not yet fully understood, and must depend on a combination of non-linear effects between rotation and convection. Only a systematic asteroseismic study of a large number of pulsating stars, and hence putting constraints on the internal properties, allows to solve this open question in astrophysics. Thanks to the recently launched space missions CoRoT and Kepler, that are providing excellent photometric time-series for thousands of pulsating stars, it is being possible to investigate for the first time the pulsational behaviour of a large enough sample of each pulsation class. With this project we will study with CoRoT and Kepler pulsators of the not-well understood class of γ Dor stars (Spectral Type A-F, M=1.2-2.5M⊙). We will model the targets, constrain the pulsation mechanism, and arrive at a first reliable seismic description of this class of pulsators.