Interior structura variations in the secondary components of two Algol-type eclipsing binary systems: SW Cygni and RR Draconis

	Interior structura variations in the secondary components of two Algol-type eclipsing binary systems: SW Cygni and RR Draconis
	Qian SB(钱声帮)1,2 ; Zhu LY(朱俐颖)1,2 ; Boonrucksar, S 3
刊名	ASTRONOMY & ASTROPHYSICS
	2002-12
卷号	396 期号:2 页码:609-613
关键词	stars : binaries : close stars : individual : SW Cyg stars : individual : RR Dra stars : evolution
ISSN号	0004-6361
通讯作者	Qian, SB (reprint author), Chinese Acad Sci, Yunnan Observ, Natl Astron Observ, POB 110, Kunming 650011, Peoples R China.
产权排序	第一完成单位
英文摘要	SW Cyg and DD Dra are two Algol-type eclipsing binary systems. Both contain an A2-type main-sequence primary and a K0-type secondary component with a rather deep primary light minimum in their light curves (2.(m)6 and 3.(m)8, respectively). In the present paper, orbital period changes of these stars are studied based on the analyses of their century-long times of light minimum. Several period jumps are found to superimpose on a rapid secular increase (dP/dt = +4.71x10(-6) and +4.24x10(-6) days/year, respectively). Since the period increases are rather rapid, the mass exchange between the components would be dynamical. SW Cyg is a low-mass ratio system (q=0.20) and it is expected that the mass ratio of RR Dra may also be very low because of the rather deep primary eclipse minimum. The rapid period increases suggest that a rapid mass transfer also occurs in a low-mass ratio Alogl-type close binary which is opposite to the theoretically evolutionary scheme of the binary star. The period jumps superimposed on the long-term increases are caused by the structura variation of the cool mass-loser via instabilities in the convective outer layer (COL) or via cyclic magnetic activity of the K0-type components. As the period jumps do not occur in a short-term alternating way, the structura change caused by instabilities in the COL via a dynamical mass loss from the cool subgiant may be more plausible.
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]	ALTERNATE PERIOD CHANGES ; CLOSE BINARIES
收录类别	SCI ; EI
原文出处	http://www.aanda.org/articles/aa/abs/2002/47/aa2923/aa2923.html
语种	英语
WOS记录号	WOS:000179574300024
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/5752]
专题	云南天文台_双星与变星研究组
作者单位	1.Yunnan Observatory, National Astronomical Observatories, Chinese Academy of Sciences, PO Box 110, 650011 Kunming, PR China 2.United Laboratory of Optical Astronomy, Chinese Academy of Science (ULOAC), PR China 3.Astronomy Research unit, Department of Physics, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
推荐引用方式 GB/T 7714	Qian SB,Zhu LY,Boonrucksar, S. Interior structura variations in the secondary components of two Algol-type eclipsing binary systems: SW Cygni and RR Draconis[J]. ASTRONOMY & ASTROPHYSICS,2002,396(2):609-613.
APA	Qian SB,Zhu LY,&Boonrucksar, S.(2002).Interior structura variations in the secondary components of two Algol-type eclipsing binary systems: SW Cygni and RR Draconis.ASTRONOMY & ASTROPHYSICS,396(2),609-613.
MLA	Qian SB,et al."Interior structura variations in the secondary components of two Algol-type eclipsing binary systems: SW Cygni and RR Draconis".ASTRONOMY & ASTROPHYSICS 396.2(2002):609-613.