湍流压对中小质量恒星后期演化的影响(I)湍流压对内部结构和演化的影响  

The Influence of Turbulent Pressure on the Late Stages of Evolution of Low and Intermediate mass Star. (II) The Effect of Turbulent Pressure on the Internal Structure and Evolution

作　　者：蒋苏云[1] 黄润乾[1] 

机构地区：[1]中国科学院云南天文台

出　　处：《天体物理学报》1998年第1期59-67,共9页

基　　金：国家自然科学基金

摘　　要：本文研究了２８Ｍ⊙和７Ｍ⊙恒星由主序到红巨星和ＡＧＢ星阶段的演化．结果发现，湍流压的存在对质量较大的７Ｍ⊙恒星的内部结构有较大的影响，它将使氢燃烧壳层明显变厚并较早地消失；使恒星中心的温度降低；使ＨＲ图中的演化轨迹向温度降低和光度减小的方向变化；使氢壳层燃烧出现周期性脉动；氦壳层的热脉动周期变短等等．但是，对于质量较小的２８Ｍ⊙恒星，湍流压的效应很微小．Our study of the evolution of a star with 7M ⊙ from the main sequence to the AGB stage shows that the effect of turbulent pressure on its internal structure and evolution is significant. Turbulent pressure makes the H burning shell thicker during the early AGB stage and vanish early; the central temperature of the star becomes lower; the evolutionary track in the HR diagram moves to the region of lower temperature and lower luminosity. In the late AGB stage of a star of 7M ⊙ turbulent pressure can cause a periodic oscillation in the luminosity, temperature and density in the H burning shell, while the cycle of the thermal pulses of the He burning shell becomes shorter. However, the evolution of a star with 2 8M ⊙ is hardly affected by the presence of turbulent pressure.

关 键 词：恒星演化 中小质量星 红巨星 AGB星 湍流压 

分 类 号：P152[天文地球—天文学]