Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry

	Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry
	Kains, N; Bramich, DM; Ferro, AA; Jaimes, RF; Jorgensen, UG; Giridhar, S; Penny, MT; Alsubai, KA; Andersen, JM; Bozza, V
刊名	ASTRONOMY & ASTROPHYSICS
	2013-07
卷号	555
关键词	stars: variables: general stars: variables: RR Lyrae globular clusters: individual: M 30 (NGC 7099)
ISSN号	0004-6361
通讯作者	Kains, N (reprint author), European So Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany.
产权排序	第十八完成单位
英文摘要	Aims. We present the analysis of 26 nights of V and I time-series observations from 2011 and 2012 of the globular cluster M 30 (NGC 7099). We used our data to search for variable stars in this cluster and refine the periods of known variables; we then used our variable star light curves to derive values for the cluster's parameters. Methods. We used difference image analysis to reduce our data to obtain high-precision light curves of variable stars. We then estimated the cluster parameters by performing a Fourier decomposition of the light curves of RR Lyrae stars for which a good period estimate was possible. We also derive an estimate for the age of the cluster by fitting theoretical isochrones to our colour-magnitude diagram (CMD). Results. Out of 13 stars previously catalogued as variables, we find that only 4 are bona fide variables. We detect two new RR Lyrae variables, and confirm two additional RR Lyrae candidates from the literature. We also detect four other new variables, including an eclipsing blue straggler system, and an SX Phoenicis star. This amounts to a total number of confirmed variable stars in M 30 of 12. We perform Fourier decomposition of the light curves of the RR Lyrae stars to derive cluster parameters using empirical relations. We find a cluster metallicity [Fe/H](ZW) = -2.01 +/- 0.04, or [Fe/H](UVES) = -2.11 +/- 0.06, and a distance of 8.32 +/- 0.20 kpc (using RR0 variables), 8.10 kpc (using one RR1 variable), and 8.35 +/- 0.42 kpc (using our SX Phoenicis star detection in M 30). Fitting isochrones to the CMD, we estimate an age of 13.0 +/- 1.0 Gyr for M 30.
学科主题	Astronomy & Astrophysics
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	RR-LYRAE VARIABLES ; DIFFERENCE IMAGE-ANALYSIS ; LARGE-MAGELLANIC-CLOUD ; DEEP CCD PHOTOMETRY ; SX PHOENICIS STARS ; METAL ABUNDANCES ; LUMINOSITY FUNCTION ; DWARF NOVAE ; M30 ; NGC-7099
收录类别	SCI ; EI
原文出处	http://www.aanda.org/articles/aa/abs/2013/07/aa21819-13/aa21819-13.html
语种	英语
WOS记录号	WOS:000322008600036
公开日期	2016-05-03
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/6793]
专题	云南天文台_系外行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
推荐引用方式 GB/T 7714	Kains, N,Bramich, DM,Ferro, AA,et al. Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry[J]. ASTRONOMY & ASTROPHYSICS,2013,555.
APA	Kains, N.,Bramich, DM.,Ferro, AA.,Jaimes, RF.,Jorgensen, UG.,...&Gu SH.(2013).Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry.ASTRONOMY & ASTROPHYSICS,555.
MLA	Kains, N,et al."Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry".ASTRONOMY & ASTROPHYSICS 555(2013).