WZ CEPHEI: A CLOSE BINARY AT THE BEGINNING OF CONTACT PHASE | |
Zhu LY(朱俐颖)1,2; Qian SB(钱声帮)1,2; Zhu, LY (reprint author), Chinese Acad Sci, Natl Astron Observ, Yunnan Observ, POB 110, Kunming 650011, Peoples R China. | |
发表期刊 | ASTRONOMICAL JOURNAL |
2009-12 | |
卷号 | 138期号:6页码:2002-2006 |
DOI | 10.1088/0004-6256/138/6/2002 |
产权排序 | 第1完成单位 |
收录类别 | SCI |
关键词 | Binaries: Close Binaries: Eclipsing Stars: Evolution Stars: Individual (Wz Cephei) |
摘要 | Photometric photoelectric data of the short-period close binary system, WZ Cephei, are presented. A new photometric analysis with the 2003 version of the Wilson-Devinney method confirmed that it is a shallow contact binary (f similar to 13.3%) with a high level of spot activity on the primary component. Combining new determined times of light minimum with the others published in the literature, the period change of the binary star is investigated. A periodic variation, with a period of 34.2 years and an amplitude of 0(d).013, was discovered to be superimposed on a long-term period decrease (dP/dt = -8.8 x 10(-8) days year(-1)). Both the secular period decrease and the shallow contact configuration suggest that this binary system is at the beginning of contact phase. It is on the way to evolving into a normal overcontact phase via secular angular momentum loss and/or mass transfer from the more massive component to the less massive one. The period oscillation can be explained either by the light-time effect due to the presence of a third body or by magnetic activity. On the one hand, if it is caused by the light-time effect, the mass and the orbital radius of the additional body should be m(3) = 0.17 M(circle dot) and a(3) = 26.6 AU, respectively, when this body is coplanar to the orbit of the eclipsing pair. On the other hand, since the system shows high levels of spot activity, the period oscillation may be explained as a consequence of magnetic cycles. In this case, the required variation of the quadrupole moment is calculated to be 9.2 x 10(49) g cm(2). |
项目资助者 | The Chinese Academy of Sciences ; Yunnan Natural Science Foundation [2008CD157] ; National Key Fundamental Research Project [2007CB815406] |
语种 | 英语 |
学科领域 | Astronomy & Astrophysics |
文章类型 | Article |
ISSN | 0004-6256 |
URL | 查看原文 |
归档日期 | 2009-11-20 |
WOS记录号 | WOS:000271630200036 |
WOS研究方向 | Astronomy & Astrophysics |
WOS类目 | Astronomy & Astrophysics |
关键词[WOS] | ORBITAL PERIOD MODULATION ; TERM STARSPOT EVOLUTION ; ACTIVITY CYCLE ; LIGHT CURVES ; PHOTOMETRIC MEASUREMENTS ; OVERCONTACT PHASE ; AR LACERTAE ; MASS ; CASSIOPEIAE ; PERSEI |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://ir.ynao.ac.cn/handle/114a53/5816 |
专题 | 双星与变星研究组 |
通讯作者 | Zhu, LY (reprint author), Chinese Acad Sci, Natl Astron Observ, Yunnan Observ, POB 110, Kunming 650011, Peoples R China. |
作者单位 | 1.National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, P.O. Box 110, 650011 Kunming, China 2.Laboratory for the Structure and Evolution of Celestial Bodies, Chinese Academy of Sciences P.O. Box 110, 650011 Kunming, China |
第一作者单位 | 中国科学院云南天文台 |
推荐引用方式 GB/T 7714 | Zhu LY,Qian SB,Zhu, LY . WZ CEPHEI: A CLOSE BINARY AT THE BEGINNING OF CONTACT PHASE[J]. ASTRONOMICAL JOURNAL,2009,138(6):2002-2006. |
APA | Zhu LY,Qian SB,&Zhu, LY .(2009).WZ CEPHEI: A CLOSE BINARY AT THE BEGINNING OF CONTACT PHASE.ASTRONOMICAL JOURNAL,138(6),2002-2006. |
MLA | Zhu LY,et al."WZ CEPHEI: A CLOSE BINARY AT THE BEGINNING OF CONTACT PHASE".ASTRONOMICAL JOURNAL 138.6(2009):2002-2006. |
条目包含的文件 | ||||||
文件名称/大小 | 文献类型 | 版本类型 | 开放类型 | 使用许可 | ||
WZ CEPHEI_ A CLOSE B(823KB) | 期刊论文 | 作者接受稿 | 开放获取 | CC BY-NC-SA | 浏览 请求全文 |
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