On the physical processes in contact binary systems

	On the physical processes in contact binary systems
	Huang RQ(黄润乾)1 ; Song HF(宋汉峰)1,2 ; Bi SL(毕少兰)1
刊名	CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS
	2007
卷号	7 期号:2 页码:235-244
关键词	stars : binaries : general stars : mass-loss stars : evolution
ISSN号	1009-9271
通讯作者	Huang, RQ (reprint author), Chinese Acad Sci, Yunnan Observ, Natl Astron Observ, Kunming 650011, Peoples R China.
产权排序	第一完成单位
英文摘要	Three important physical processes occurring in contact binary systems are studied. The first one is the effect of spin, orbital rotation and tide on the structure of the components, which includes also the effect of meridian circulation on the mixing of the chemical elements in the components. The second one is the mass and energy exchange between the components. To describe the energy exchange, a new approach is introduced based on the understanding that the exchange is due to the release of the potential, kinetic and thermal energy of the exchanged mass. The third is the loss of mass and angular momentum through the outer Lagrangian point. The rate of mass loss and the angular momentum carried away by the lost mass are discussed. To show the effects of these processes, we follow the evolution of a binary system consisting of a 12M(circle dot) and a 5M(circle dot) star with mass exchange between the components and mass loss via the outer Lagrangian point, both with and without considering the effects of rotation and tide. The result shows that the effect of rotation and tide advances the start of the semi-detached and the contact phases, and delays the end of the hydrogen-buming phase of the primary. Furthermore, it can change not only the occurrence of mass and angular momentum loss via the outer Lagrangian point, but also the contact or semi-contact status of the system. Thus, this effect can result in the special phenomenon of short-term variations occurring over a slow increase of the orbital period. The occurrence of mass and angular momentum loss via the outer Lagrangian point can affect the orbital period of the system significantly, but this process can be influenced, even suppressed out by the effect of rotation and tide. The mass and energy exchange occurs in the common envelope. The net result of the mass exchange process is a mass transfer from the primary to the secondary during the whole contact phase.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	EVOLUTION ; STABILITY
收录类别	SCI
原文出处	http://iopscience.iop.org/1009-9271/7/2/07/
语种	英语
WOS记录号	WOS:000246129300007
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/5189]
专题	云南天文台_恒星物理研究组
作者单位	1.National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011 2.Graduate University of Chinese Academy of Sciences, Beijing 100049
推荐引用方式 GB/T 7714	Huang RQ,Song HF,Bi SL. On the physical processes in contact binary systems[J]. CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS,2007,7(2):235-244.
APA	Huang RQ,Song HF,&Bi SL.(2007).On the physical processes in contact binary systems.CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS,7(2),235-244.
MLA	Huang RQ,et al."On the physical processes in contact binary systems".CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS 7.2(2007):235-244.