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题名	用天文观测验证相接双星理论模型
作者	罗常青
学位类别	博士
答辩日期	2011-10-17
授予单位	中国科学院研究生院（云南天文台）
授予地点	北京
导师	黄润乾
关键词	相接双星 双星结构演化 测光观测
其他题名	Inspection of the contact binaries model by astronomical observations
学位专业	天体物理
中文摘要	相接双星是一类特殊的双星。两子星相距很近，都充满洛希瓣，并形成公共包层。两子星因为受到自转和公转离心力作用，以及相互之间的强引力作用（潮汐作用），可以造成两子星的结构，内部物理过程和演化发生变化，还可以造成两子星之间发生物质交换和能量交换，并严重改变双星的轨道运动。因此研究相接双星的结构与演化不仅可以认识相接双星中的各种复杂物理过程，而且可以对整个双星世界和恒星系统，乃至整个银河系的认识都有重要的意义。 半个多世纪以来曾经出现了许多相接双星理论模型，各种理论模型都对相接双星中的物理过程有特殊的见解和处理方法。但是这些模型都不能很好地解释相接双星的许多天文观测现象和规律。而天文观测现象和规律是检验理论模型是否正确的最有效工具。近年来由Huang, Song，Bi等人提出了一个新的相接双星理论模型（Huang et al. 2007; Song et al.2007）, 简称HSB相接双星理论模型。这个模型在处理相接双星中的复杂物理过程时和以前模型十分不同，有其独特的见解和处理方法，包括相接双星的物质和能量交换过程是两个密不可分的过程，用两颗子星的平均势做判断，物质在交流的过程中会携带相应的能量，这里的能量包括势能，动能，热能。同时考虑了转动潮汐效应，考虑此效应后，子星结构从球形变为非球形结构，还会出现子午环流等复杂的物理过程，最后还考虑了外拉格朗日点点的物质和角动量损失。 本论文的目的和内容，就是要用天文观测得到的相接双星的规律，检验HSB相接双星理论模型，检验这个理论模型是否可以解释大、中、小质量相接双星的各种观测规律。我们的一个工作是采用光变曲线中的食深与质量、半径关系来检验HSB模型。将理论和观测的两组关系进行比较，发现观测和理论能很好的符合。这证明HSB相接双星理论模型既可以适用于大、中、小质量相接双星，同时也证明这个模型可以解释较多的相接双星的观测现象和规律。第二个工作是用观测到的相接双星光变曲线的食深和极大值附近的宽度（HW），检验相接双星的子星是否该考虑成非球形结构。最后同观测进行比较，发现非球形结构的理论光变曲线更接近观测数据。此结果证明转动和潮汐效应对光变曲线的影响很大，所以在相接双星演化模型中子星应该考虑成非球形结构。
英文摘要	Contact binaries are one kind of special close binaries that the two components have filled their Roche lobes, and have a common envelope. The two components are subject to centrifugal force caused by rotation and revolution and to strong gravitational action between each other (tidal action). These interactions can give rise to changes of the two components' structures, internal physical processes and evolution, causing the mass transfer and energy exchange between the two components and changes on the orbital motion of the binaries. Therefore, investigations on the structure and evolution of the contact binaries are significant and very useful for understanding the complex physical processes and the structures of binary stars. For more than half a century, many theoretical models of contact binaries have been built, which have special views and different methods for treating the physical processes of contact binaries. The models can explain some astronomical observation phenomena, but they still have some difficulties for some other phenomena. As we all know, confirming whether the theoretical model is correct or not, the astronomical observation phenomena and regularity is the most effective tool. Recently, a new contact binary model was developed by Huang, Song and Bi (Huang et al. 2007; Song et al. 2007, and hereafter refered to as HSB contact binary model). In dealing with the complex physical processes, HSB model has a lot of differences. Some understandings and treatments of physical processes are as follows: The first is considering the mass and energy transfer as two closely related and inseparable processes. This means that the exchanged mass brings simultaneously potential, kinetic and thermal energy to the companion and causes the energy exchange between the components. The second is considering the effects of rotation and tide, which changes the structure of the two components from spherical symmetric to non-spherical symmetric. These effects also lead to occurrences of meridian circulation in the components, which result in the mixing of the chemical elements and angular momentum transfer .The last one is the possible mass loss and angular momentum loss via the outer Lagrangian point when the common envelope expands to reach this point. The aim of this paper is to inspect the HSB contact binary model by some regularities which obtained from astronomical observations and to confirm whether this model can explain the observational regularity of massive, intermediate-mass contact binaries and low-mass contact binaries. The first work is inspection of the HSB contact binary model by two relationships of ED of light curve with mass and radius. The results show a good agreement for contact binary systems with all different masses and explain some observational regularities. The second work is contrasting the eclipsing depth and width nearby the maximum of observational and theoretical light curves, the structure of the two components should be known directly to be spherical or non-spherical. Comparing with the observations, the results show that non-spherical structure is in better agreement with the observation. So the structure of the two components should be non-spherical symmetric.
语种	中文
学科主题	天文学
内容类型	学位论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/5332]
专题	云南天文台_恒星物理研究组
推荐引用方式 GB/T 7714	罗常青. 用天文观测验证相接双星理论模型[D]. 北京. 中国科学院研究生院（云南天文台）. 2011.

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