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

N. Kains; D. M. Bramich; A. Arellano Ferro; Roberto Jose Figuera Jaimes; U. G. Jorgensen; S. Giridhar; M. T. Penny; K. A. Alsubai; J. M. Andersen; V. Bozza; Paul Browne; M. Burgdorf; S. Calchi Novati; Y. Damerdji; C. Diehl; Peter Dodds; Martin Dominik; A. Elyiv; X. -S. Fang; E. Giannini; S. -H. Gu; S. Hardis; K. Harpsoe; T. C. Hinse; A. Hornstrup; Markus Peter Gerhard Hundertmark; J. Jessen-Hansen; D. Juncher; E. Kerins; H. Kjeldsen; H. Korhonen; C. Liebig; M. N. Lund; M. Lundkvist; L. Mancini; R. Martin; M. Mathiasen; M. Rabus; S. Rahvar; D. Ricci; K. Sahu; G. Scarpetta; J. Skottfelt; C. Snodgrass; J. Southworth; J. Surdej; J. Tregloan-Reed; C. Vilela; O. Wertz; A. Williams

doi:10.1051/0004-6361/201321819

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

N. Kains^*, D. M. Bramich, A. Arellano Ferro, Roberto Jose Figuera Jaimes, U. G. Jorgensen, S. Giridhar, M. T. Penny, K. A. Alsubai, J. M. Andersen, V. Bozza, Paul Browne, M. Burgdorf, S. Calchi Novati, Y. Damerdji, C. Diehl, Peter Dodds, Martin Dominik, A. Elyiv, X. -S. Fang, E. GianniniS. -H. Gu, S. Hardis, K. Harpsoe, T. C. Hinse, A. Hornstrup, Markus Peter Gerhard Hundertmark, J. Jessen-Hansen, D. Juncher, E. Kerins, H. Kjeldsen, H. Korhonen, C. Liebig, M. N. Lund, M. Lundkvist, L. Mancini, R. Martin, M. Mathiasen, M. Rabus, S. Rahvar, D. Ricci, K. Sahu, G. Scarpetta, J. Skottfelt, C. Snodgrass, J. Southworth, J. Surdej, J. Tregloan-Reed, C. Vilela, O. Wertz, A. Williams

^*Corresponding author for this work

School of Physics and Astronomy

Research output: Contribution to journal › Article › peer-review

Abstract

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.

Original language	English
Article number	A36
Number of pages	15
Journal	Astronomy & Astrophysics
Volume	555
Early online date	25 Jun 2013
DOIs	https://doi.org/10.1051/0004-6361/201321819
Publication status	Published - Jul 2013

Keywords

Stars: variables: general
Stars: variables: RR Lyrae
Globular clusters: individual: M 30 (NGC 7099)
RR-lyrae variables
Difference image-analysis
Large-magellanic-cloud
Deep CCD photometry
SX phoenicis stars
Metal abundances
Luminosity function
Dwarf novae
M30
NGC-7099

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Jaimes_2013_AA_Estimating
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Kains, N., Bramich, D. M., Arellano Ferro, A., Figuera Jaimes, R. J., Jorgensen, U. G., Giridhar, S., Penny, M. T., Alsubai, K. A., Andersen, J. M., Bozza, V., Browne, P., Burgdorf, M., Calchi Novati, S., Damerdji, Y., Diehl, C., Dodds, P., Dominik, M., Elyiv, A., Fang, X. .-S., ... Williams, A. (2013). Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry. Astronomy & Astrophysics, 555, Article A36. https://doi.org/10.1051/0004-6361/201321819

@article{47d2ddd880e0476db2a7fcb99c370bf8,

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

abstract = "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.",

keywords = "Stars: variables: general, Stars: variables: RR Lyrae, Globular clusters: individual: M 30 (NGC 7099), RR-lyrae variables, Difference image-analysis, Large-magellanic-cloud, Deep CCD photometry, SX phoenicis stars, Metal abundances, Luminosity function, Dwarf novae, M30, NGC-7099",

author = "N. Kains and Bramich, {D. M.} and {Arellano Ferro}, A. and {Figuera Jaimes}, {Roberto Jose} and Jorgensen, {U. G.} and S. Giridhar and Penny, {M. T.} and Alsubai, {K. A.} and Andersen, {J. M.} and V. Bozza and Paul Browne and M. Burgdorf and {Calchi Novati}, S. and Y. Damerdji and C. Diehl and Peter Dodds and Martin Dominik and A. Elyiv and Fang, {X. -S.} and E. Giannini and Gu, {S. -H.} and S. Hardis and K. Harpsoe and Hinse, {T. C.} and A. Hornstrup and Hundertmark, {Markus Peter Gerhard} and J. Jessen-Hansen and D. Juncher and E. Kerins and H. Kjeldsen and H. Korhonen and C. Liebig and Lund, {M. N.} and M. Lundkvist and L. Mancini and R. Martin and M. Mathiasen and M. Rabus and S. Rahvar and D. Ricci and K. Sahu and G. Scarpetta and J. Skottfelt and C. Snodgrass and J. Southworth and J. Surdej and J. Tregloan-Reed and C. Vilela and O. Wertz and A. Williams",

note = "N.K. acknowledges an ESO Fellowship. The research leading to these results has received funding from the European Community{\textquoteright}s Seventh Framework Programme (/FP7/2007-2013/) under grant agreement No. 229517. A.A.F. acknowledges the support of DGAPA-UNAM through project IN104612. A.A.F. and S.G. are thankful to the CONACyT (M{\'e}xico) and the Department of Science and Technology (India) for financial support under the Indo-Mexican collaborative project DST/INT/MEXICO/RP001/2008. O.W. (aspirant FRS – FNRS), A.E. (post-doc PRODEX), Y.D. (post-doc PRODEX) and J. Surdej acknowledge support from the Communaut{\'e} fran{\c c}aise de Belgique – Actions de recherche concert{\'e}es – Acad{\'e}mie universitaire Wallonie-Europe. T.C.H. gratefully acknowledges financial support from the Korea Research Council for Fundamental Science and Technology (KRCF) through the Young Research Scientist Fellowship Program. T.C.H. acknowledges financial support from KASI (Korea Astronomy and Space Science Institute) grant number 2012-1-410-02. K.A., D.B., M.D., M.H., and C.L. are supported by NPRP grant NPRP-09-476-1-78 from the Qatar National Research Fund (a member of Qatar Foundation). The Danish 1.54 m telescope is operated based on a grant from the Danish Natural Science Foundation (FNU). Funding for the Stellar Astrophysics Centre at Aarhus University is provided by The Danish National Research Foundation. This research was supported in part by the project ASTERoseismic Investigations with SONG and Kepler (ASTERISK), funded by the European Research Council (grant agreement No.: 267864). C.S. received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 268421. C.H.G. and X.S.F. acknowledge support from National Natural Science Foundation of China (grants Nos. 10373023 and 10773027). H.K. acknowledges support from a Marie-Curie Intra-European Fellowship. ",

year = "2013",

month = jul,

doi = "10.1051/0004-6361/201321819",

language = "English",

volume = "555",

journal = "Astronomy & Astrophysics",

issn = "0004-6361",

publisher = "EDP SCIENCES S A",

}

Kains, N, Bramich, DM, Arellano Ferro, A, Figuera Jaimes, RJ, Jorgensen, UG, Giridhar, S, Penny, MT, Alsubai, KA, Andersen, JM, Bozza, V, Browne, P, Burgdorf, M, Calchi Novati, S, Damerdji, Y, Diehl, C, Dodds, P, Dominik, M, Elyiv, A, Fang, X-S, Giannini, E, Gu, S-H, Hardis, S, Harpsoe, K, Hinse, TC, Hornstrup, A, Hundertmark, MPG, Jessen-Hansen, J, Juncher, D, Kerins, E, Kjeldsen, H, Korhonen, H, Liebig, C, Lund, MN, Lundkvist, M, Mancini, L, Martin, R, Mathiasen, M, Rabus, M, Rahvar, S, Ricci, D, Sahu, K, Scarpetta, G, Skottfelt, J, Snodgrass, C, Southworth, J, Surdej, J, Tregloan-Reed, J, Vilela, C, Wertz, O & Williams, A 2013, 'Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry', Astronomy & Astrophysics, vol. 555, A36. https://doi.org/10.1051/0004-6361/201321819

TY - JOUR

T1 - Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry

AU - Kains, N.

AU - Bramich, D. M.

AU - Arellano Ferro, A.

AU - Figuera Jaimes, Roberto Jose

AU - Jorgensen, U. G.

AU - Giridhar, S.

AU - Penny, M. T.

AU - Alsubai, K. A.

AU - Andersen, J. M.

AU - Bozza, V.

AU - Browne, Paul

AU - Burgdorf, M.

AU - Calchi Novati, S.

AU - Damerdji, Y.

AU - Diehl, C.

AU - Dodds, Peter

AU - Dominik, Martin

AU - Elyiv, A.

AU - Fang, X. -S.

AU - Giannini, E.

AU - Gu, S. -H.

AU - Hardis, S.

AU - Harpsoe, K.

AU - Hinse, T. C.

AU - Hornstrup, A.

AU - Hundertmark, Markus Peter Gerhard

AU - Jessen-Hansen, J.

AU - Juncher, D.

AU - Kerins, E.

AU - Kjeldsen, H.

AU - Korhonen, H.

AU - Liebig, C.

AU - Lund, M. N.

AU - Lundkvist, M.

AU - Mancini, L.

AU - Martin, R.

AU - Mathiasen, M.

AU - Rabus, M.

AU - Rahvar, S.

AU - Ricci, D.

AU - Sahu, K.

AU - Scarpetta, G.

AU - Skottfelt, J.

AU - Snodgrass, C.

AU - Southworth, J.

AU - Surdej, J.

AU - Tregloan-Reed, J.

AU - Vilela, C.

AU - Wertz, O.

AU - Williams, A.

N1 - N.K. acknowledges an ESO Fellowship. The research leading to these results has received funding from the European Community’s Seventh Framework Programme (/FP7/2007-2013/) under grant agreement No. 229517. A.A.F. acknowledges the support of DGAPA-UNAM through project IN104612. A.A.F. and S.G. are thankful to the CONACyT (México) and the Department of Science and Technology (India) for financial support under the Indo-Mexican collaborative project DST/INT/MEXICO/RP001/2008. O.W. (aspirant FRS – FNRS), A.E. (post-doc PRODEX), Y.D. (post-doc PRODEX) and J. Surdej acknowledge support from the Communauté française de Belgique – Actions de recherche concertées – Académie universitaire Wallonie-Europe. T.C.H. gratefully acknowledges financial support from the Korea Research Council for Fundamental Science and Technology (KRCF) through the Young Research Scientist Fellowship Program. T.C.H. acknowledges financial support from KASI (Korea Astronomy and Space Science Institute) grant number 2012-1-410-02. K.A., D.B., M.D., M.H., and C.L. are supported by NPRP grant NPRP-09-476-1-78 from the Qatar National Research Fund (a member of Qatar Foundation). The Danish 1.54 m telescope is operated based on a grant from the Danish Natural Science Foundation (FNU). Funding for the Stellar Astrophysics Centre at Aarhus University is provided by The Danish National Research Foundation. This research was supported in part by the project ASTERoseismic Investigations with SONG and Kepler (ASTERISK), funded by the European Research Council (grant agreement No.: 267864). C.S. received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 268421. C.H.G. and X.S.F. acknowledge support from National Natural Science Foundation of China (grants Nos. 10373023 and 10773027). H.K. acknowledges support from a Marie-Curie Intra-European Fellowship.

PY - 2013/7

Y1 - 2013/7

N2 - 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.

AB - 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.

KW - Stars: variables: general

KW - Stars: variables: RR Lyrae

KW - Globular clusters: individual: M 30 (NGC 7099)

KW - RR-lyrae variables

KW - Difference image-analysis

KW - Large-magellanic-cloud

KW - Deep CCD photometry

KW - SX phoenicis stars

KW - Metal abundances

KW - Luminosity function

KW - Dwarf novae

KW - M30

KW - NGC-7099

UR - http://www.aanda.org/articles/aa/olm/2013/07/aa21819-13/aa21819-13.html

U2 - 10.1051/0004-6361/201321819

DO - 10.1051/0004-6361/201321819

M3 - Article

SN - 0004-6361

VL - 555

JO - Astronomy & Astrophysics

JF - Astronomy & Astrophysics

M1 - A36

ER -

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

Abstract

Keywords

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

Abstract

Keywords

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Astrophysics at St Andrews:2012 - 2014: Astrophysics at St Andrews: 2012 - 2014

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