An orbital period investigation of the Algol-type eclipsing binary VW Hydrae

	An orbital period investigation of the Algol-type eclipsing binary VW Hydrae
	Zhang J(张嘉)1,2 ; Qian SB(钱声帮)1 ; Soonthornthum, B 3
刊名	RESEARCH IN ASTRONOMY AND ASTROPHYSICS
	2009-03
卷号	9 期号:3 页码:307-314
关键词	stars: binaries: close stars: binaries: eclipsing multiple stars stars: individual (VW Hya)
ISSN号	1674-4527
通讯作者	Zhang, J (reprint author), Chinese Acad Sci, Natl Astron Observ, Yunnan Observ, Kunming 650011, Peoples R China.
产权排序	第一完成单位
英文摘要	Orbital period variations of the Algol-type eclipsing binary, VW Hydrae, are analyzed based on one newly determined eclipse time and the other times of light minima collected from the literature. It is discovered that the orbital period shows a continuous increase at arate of dP/dt = +6.34 x 10(-7) d yr(-1) while it undergoes acyclic change with an amplitude of 0.0639 d and a period of 51.5 yr. After the long-term period increase and the large-amplitude period oscillation were subtracted from the O-C curve, the residuals of the photoelectric and CCD data indicate a small-amplitude cyclic variation with a period of 8.75 yr and a small amplitude of 0.0048 d. The continuous period increase indicates a conservative mass transfer at a rate of dM(2)/dt = 7.89 x 10(-8) M(circle dot) yr(-1) from the secondary to the primary. The period increase may be caused by a combination of the mass transfer from the secondary to the primary and the angular momentum transfer from the binary system to the circumbinary disk. The two cyclic period oscillations can be explained by light-travel time effects via the presence of additional bodies. The small-amplitude periodic change indicates the existence of a less massive component with mass M(3) > 0.53 M(circle dot), while the large-amplitude one is caused by the presence of a more massive component with mass M(4) > 2.84 M(circle dot). The ultraviolet source in the system reported by Kviz & Rufener (1987) may be one of the additional components, and it is possible that the more massive one may be an unseen neutron star or black hole. The rapid period increase and the possibility of the presence of two additional components in the binary make it a very interesting system to study. New photometric and high-resolution spectroscopic observations and a detailed investigation of those data are required m the future.
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]	CLOSE BINARIES ; MASS-TRANSFER ; LIGHT CURVES ; MODULATION ; SYSTEMS ; CYGNI
收录类别	SCI
原文出处	http://iopscience.iop.org/1674-4527/9/3/005/
语种	英语
WOS记录号	WOS:000264845200005
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/5828]
专题	云南天文台_双星与变星研究组
作者单位	1.National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011, China 2.Graduate School of the Chinese Academy of Sciences, Beijing 100039, China 3.National Astronomical Research Institute of Thailand/Ministry of Science and Technology, Bangkok, Thailand
推荐引用方式 GB/T 7714	Zhang J,Qian SB,Soonthornthum, B. An orbital period investigation of the Algol-type eclipsing binary VW Hydrae[J]. RESEARCH IN ASTRONOMY AND ASTROPHYSICS,2009,9(3):307-314.
APA	Zhang J,Qian SB,&Soonthornthum, B.(2009).An orbital period investigation of the Algol-type eclipsing binary VW Hydrae.RESEARCH IN ASTRONOMY AND ASTROPHYSICS,9(3),307-314.
MLA	Zhang J,et al."An orbital period investigation of the Algol-type eclipsing binary VW Hydrae".RESEARCH IN ASTRONOMY AND ASTROPHYSICS 9.3(2009):307-314.