OPTICAL FLARES AND A LONG-LIVED DARK SPOT ON A COOL SHALLOW CONTACT BINARY

	OPTICAL FLARES AND A LONG-LIVED DARK SPOT ON A COOL SHALLOW CONTACT BINARY
	Qian SB(钱声帮)1,2,3 ; Wang JJ(王晶晶)1,2,3 ; Zhu LY(朱俐颖)1,2,3 ; Snoonthornthum, B 4; Wang, LZ 5; Zhao EG(赵二刚)1,2 ; Zhou X(周肖)1,2,3 ; Liao WP(廖文萍)1,2 ; Liu NP(刘念平)1,2,3
刊名	ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
	2014-05
卷号	212 期号:1 页码:4-18
关键词	binaries: close binaries: eclipsing stars: activity stars: evolution stars: individual (CSTAR 038663)
ISSN号	0067-0049
通讯作者	Qian, SB (reprint author), Chinese Acad Sci, Yunnan Observ, POB 110, Kunming 650011, Yunnan, Peoples R China.
产权排序	第一完成单位
英文摘要	W UMa-type stars are contact systems where both cool components fill the critical Roche lobes and share a common convective envelope. Long and unbroken time-series photometry is expected to play an important role in their origin and activity. The newly discovered short-period W UMa-type star, CSTAR 038663, was monitored continuously by Chinese Small Telescope ARray (CSTAR) in Antarctica during the winters of 2008 and 2010. There were 15 optical flares recorded in the i band during the winter of 2010. This was the first time such flares were detected from a W UMa-type star. By analyzing the nearly unbroken photometric data from 2008, it is discovered that CSTAR 038663 is a W-type shallow contact binary system (f = 10.6(+/- 2.9)%) with a high mass ratio of q = 1.12(+/- 0.01), where the less massive component is slightly hotter than the more massive one. The asymmetric light curves are explained by the presence of a dark spot on the more massive component. Its temperature is about 800 K lower than the stellar photosphere and it covers 2.1% of the total photospheric surface. The lifetime of the dark spot is longer than 116 days. Using 725 eclipse times, we found that the observed-calculated (O-C) curve may show a cyclic variation that is explained by the presence of a close-in third body. Both the shallow contact configuration and the extremely high mass ratio suggest that CSTAR 038663 is presently evolving into a contact system with little mass transfer. The formation and evolution is driven by the loss of angular momentum via magnetic braking, and the close-in companion star is expected to play an important role, removing angular momentum from the central eclipsing binary.
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]	4-COLOR LIGHT CURVES ; CLOSE-BINARY ; OBSERVATIONAL DATA ; ECLIPSING BINARY ; VARIABLE-STARS ; PERIOD CHANGES ; MASS-RATIO ; DOME ; ANTARCTICA ; SYSTEM
收录类别	SCI
原文出处	http://iopscience.iop.org/article/10.1088/0067-0049/212/1/4/meta
语种	英语
WOS记录号	WOS:000339232600004
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/5901]
专题	云南天文台_双星与变星研究组云南天文台_中国科学院天体结构与演化重点实验室
作者单位	1.Yunnan Observatories, Chinese Academy of Sciences (CAS), P.O. Box 110, 650011 Kunming, China 2.Key laboratory of the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, P.O. Box 110, 650011 Kunming, China 3.University of the Chinese Academy of Sciences, Yuquan Road 19#, Sijingshang Block, 100049 Beijing, China 4.National Astronomical Research Insititude of Thailand, 191 Siriphanich Bldg., Huay Kaew Rd., Chiang Mai 50200, Thailand 5.National Astronomical Observatories, Chinese Academy of Sciences, 100012 Beijing, China
推荐引用方式 GB/T 7714	Qian SB,Wang JJ,Zhu LY,et al. OPTICAL FLARES AND A LONG-LIVED DARK SPOT ON A COOL SHALLOW CONTACT BINARY[J]. ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES,2014,212(1):4-18.
APA	Qian SB.,Wang JJ.,Zhu LY.,Snoonthornthum, B.,Wang, LZ.,...&Liu NP.(2014).OPTICAL FLARES AND A LONG-LIVED DARK SPOT ON A COOL SHALLOW CONTACT BINARY.ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES,212(1),4-18.
MLA	Qian SB,et al."OPTICAL FLARES AND A LONG-LIVED DARK SPOT ON A COOL SHALLOW CONTACT BINARY".ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES 212.1(2014):4-18.