密近双星自转的测量和研究(V)轨道圆化  

Measurement and Study of Rotation in Close Binary Stars (V) Orbital Circularization

作　　者：潘开科[1,2] 谭徽松[1,2] 

机构地区：[1]中国科学院云南天文台 [2]中国科学院光学天文联合开放实验室

出　　处：《天体物理学报》1997年第4期386-392,共7页

基　　金：国家自然科学基金;国家攀登计划

摘　　要：作为密近双星自转测量和研究的系列文章之一，本文从轨道圆化的角度讨论了Ｚａｈｎ的动力学潮汐机制及粘滞理论、Ｔａｓｏｕｌ的纯流体动力学理论与实测数据的符合程度．对前文（文ＩＶ）中的２９个不相接双星系统，均分别计算出了以上理论所预期的轨道圆化时标，分析比较了各系统的理论圆化时标与它的年龄及轨道圆化程度间的关系．结果表明：动力学潮汐、粘滞理论的计算结果比纯流体动力学机制的预期更符合实测数据．但与文（ＩＶ）的结果相比，动力学潮汐、粘滞理论对轨道圆化过程的预期不如它对自转同步问题的预期那样准确．本文认为，动力学潮汐和气体沾滞是密近双星系统轨道圆化的两种主要机制，但决不是唯一的机制．在主序前和ＡＧＢ后两演化阶段。In this paper, we calculate the characteristic times of orbital circularization for 29 “normal” detached binary systems in Paper (IV), in accordance with Zahn's dynamical and equilibrium tide mechanisms and Tassoul's purely hydrodynamic theory. By comparing the age of each system and its theoretical characteristic time of orbital circularization, we analyze the observed orbital eccentricity of each system and the theoretical predictions on circularization by the above theories. Basically, we find that the predictions by Zahn's mechanisms fit the observations better than those by the hydrodynamic theory, and that dynamical and equilibrium tides seem to be two of the main circularizing mechanisms for close binary systems on the main sequence. However, we also note that some other mechanisms are absolutely necessary in order to fully explain circularization processes in close binaries, especially in understanding the circular orbits of some systems with asynchronous components. We suggest that the purely hydrodynamic theory is probably important during the periods of pre main sequence and post AGB evolution of close binary systems.

关 键 词：恒星 密近双星 轨道圆化 双星 

分 类 号：P153[天文地球—天文学] P152