Preliminary investigation of period changes of five RR Lyrae stars in the Globular Cluster M15

	Preliminary investigation of period changes of five RR Lyrae stars in the Globular Cluster M15
	Li K(李凯); Qian SB(钱声帮)
	2012
会议名称	9th Pacific Rim Conference on Stellar Astrophysics
会议日期	2011-04-14
会议地点	Lijiang, PEOPLES R CHINA
卷号	451
页码	351-354
通讯作者	Li, K (reprint author), Chinese Acad Sci, Natl Astron Observ, Yunnan Observ, POB 110, Kunming 650011, Peoples R China.
英文摘要	More than a century of observations of MI5 allow us to investigate period changes of RR lyrae stars in it. We find five of them to do deep analysis because period changes of the five are very special and simple polynomials can not fit their 0 C diagrams well. The five stars are V11, V13, V15, V40 and V44, respectively. We collect all the times of light maximum from literatures. And then we get our own by observing M15 in November, 2009 using the 60cm telescope in Yunnan Observatory. Base on that we reanalyze period changes of the five stars. We find that all their O-C diagrams can fit by a secular increase or decrease and a cyclic change. If the cyclic changes are caused by the light-travel time effect, they are all in binary systems. Because we could not observe the companion objects from our telescope optically, we think the companion objects are all compact objects, this makes basis for seeking compact objects in Globular Clusters (GCs), and all of the five stars are in the outer region of MI5, so this can make some constrains on the evolution of GCs. The five stars are all RR Lyrae stars, so their period changes can also caused by the Blazhko effect and other mechanisms. We should do more observation and discussion to omit the influence of these factors in the future.
收录类别	CPCI
产权排序	第一完成单位
会议录	Astronomical Society of the Pacific (ASP) Conference Series - NINTH PACIFIC RIM CONFERENCE ON STELLAR ASTROPHYSICS
会议录出版者	ASTRONOMICAL SOC PACIFIC
会议录出版地	390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA
学科主题	Astronomy & Astrophysics
语种	英语
ISBN号	978-1-58381-785-8
WOS记录号	WOS:000304126300059
研究领域[WOS]	Astronomy & Astrophysics
内容类型	会议论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/5963]
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	Chinese Acad Sci, Natl Astron Observ, Yunnan Observ, Kunming 650011, Peoples R China
推荐引用方式 GB/T 7714	Li K,Qian SB. Preliminary investigation of period changes of five RR Lyrae stars in the Globular Cluster M15[C]. 见:9th Pacific Rim Conference on Stellar Astrophysics. Lijiang, PEOPLES R CHINA. 2011-04-14.