湍流应力对中等质量转动恒星演化的影响

The Influence of Turbulent Stress on Intermediate-Mass Star with Rotation

以恒星结构与演化理论中常用的混合程理论为基础,将湍流应力和自转离心力引入传统恒星结构模型中的流体静力学平衡方程,得到了考虑湍流应力作用下转动恒星的结构模型.并计算了一8M⊙恒星从主序星到早期AGB星的演化.研究表明:湍流应力对恒星的结构并无明显的影响,但使得恒星在各个演化阶段的寿命发生不同程度的改变;而且对流区域越大,恒星的演化寿命变化越大;对恒星在AGB星以前的演化轨迹也无明显的影响,使AGB星在赫罗图中的演化向有效温度降低、表面光度降低方向偏转,更加接近观测事实.

Based on the mixing-length theory of convection, introducing turbulent stress into hydrostatics equation of the structural and evolutionary model of star with rotation, this study has deduced the structural model of rotational star, and computed the evolution of the Star with 8Mo from ZAMS to pre-AGB stage. The results show that the turbulent stress has little influence on the stellar structure, but it can make lifetime of every stages change in different extent; and the larger the area of the convection is, the more changes of the lifetime has. There isn＇t apparent influence of the turbulent stress on evolution before the AGB stage, and the evolutionary track on the AGB stage in the HR diagram moves to the region of lower temperature and lower luminosity.