A detailed census of variable stars in the globular cluster NGC 6333 (M9) from CCD differential photometry

A. Arellano Ferro, D. M. Bramich, R. Figuera Jaimes, Sunetra Giridhar, N. Kains, K. Kuppuswamy, U. G. Jørgensen, Khalid Al-Subai, J. M. Andersen, V. Bozza, P. Browne, S. Calchi Novati, Y. Damerdji, C. Diehl, M. Dominik, S. Dreizler, A. Elyiv, E. Giannini, K. Harpsøe, F. V. Hessman & 20 others T. C. Hinse, M. Hundertmark, D. Juncher, E. Kerins, H. Korhonen, C. Liebig, L. Mancini, M. Mathiasen, M. T. Penny, M. Rabus, S. Rahvar, D. Ricci, G. Scarpetta, J. Skottfelt, C. Snodgrass, J. Southworth, J. Surdej, J. Tregloan-Reed, C. Vilela, O. Wertz

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

We report CCD V and I time series photometry of the globular cluster NGC 6333 (M9). The technique of difference image analysis has been used, which enables photometric precision better than 0.05 mag for stars brighter than V ~ 19.0 mag, even in the crowded central regions of the cluster. The high photometric precision has resulted in the discovery of twonew RRc stars, three eclipsing binaries, seven long-term variables and one field RRab star behind the cluster. A detailed identification chart and equatorial coordinates are given for all the variable stars in the field of our images of the cluster. Our data together with the literature V-data obtained in 1994 and 1995 allowed us to refine considerably the periods for all RR Lyrae stars. The nature of the new variables is discussed. We argue that variable V12 is a cluster member and an Anomalous Cepheid. Secular period variations, doublemode pulsations and/or the Blazhko-like modulations in some RRc variables are addressed. Through the light-curve Fourier decomposition of 12 RR Lyrae stars we have calculated a mean metallicity of [Fe/H]ZW = -1.70 ± 0.01(statistical) ± 0.14(systematic) or [Fe/H]UVES = -1.67 ± 0.01(statistical) ± 0.19(systematic). Absolute magnitudes, radii and masses are also estimated for the RR Lyrae stars. A detailed search for SX Phe stars in the Blue Straggler region was conducted but none were discovered. If SX Phe exist in the cluster then their amplitudes must be smaller than the detection limit of our photometry. The colour-magnitude diagram has been corrected for heavy differential reddening using the detailed extinction map of the cluster of Alonso-García et al. This has allowed us to set the mean cluster distance from two independent estimates; from the RRab and RRc absolute magnitudes, we find 8.04 ± 0.19 and 7.88 ± 0.30 kpc, respectively.

Original languageEnglish
Pages (from-to)1220-1238
Number of pages19
JournalMonthly Notices of the Royal Astronomical Society
Volume434
Issue number2
DOIs
Publication statusPublished - 1 Sep 2013

Fingerprint

census
variable stars
globular clusters
photometry
charge coupled devices
stars
image analysis
extinction
diagram
time series
decomposition
star distribution
color-magnitude diagram
charts
light curve
metallicity
modulation
radii
estimates

Keywords

  • Globular clusters: individual: NGC 6333
  • Stars: fundamental parameters
  • Stars: variables: general
  • Stars: variables: RR Lyrae

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

A detailed census of variable stars in the globular cluster NGC 6333 (M9) from CCD differential photometry. / Ferro, A. Arellano; Bramich, D. M.; Jaimes, R. Figuera; Giridhar, Sunetra; Kains, N.; Kuppuswamy, K.; Jørgensen, U. G.; Al-Subai, Khalid; Andersen, J. M.; Bozza, V.; Browne, P.; Calchi Novati, S.; Damerdji, Y.; Diehl, C.; Dominik, M.; Dreizler, S.; Elyiv, A.; Giannini, E.; Harpsøe, K.; Hessman, F. V.; Hinse, T. C.; Hundertmark, M.; Juncher, D.; Kerins, E.; Korhonen, H.; Liebig, C.; Mancini, L.; Mathiasen, M.; Penny, M. T.; Rabus, M.; Rahvar, S.; Ricci, D.; Scarpetta, G.; Skottfelt, J.; Snodgrass, C.; Southworth, J.; Surdej, J.; Tregloan-Reed, J.; Vilela, C.; Wertz, O.

In: Monthly Notices of the Royal Astronomical Society, Vol. 434, No. 2, 01.09.2013, p. 1220-1238.

Research output: Contribution to journalArticle

Ferro, AA, Bramich, DM, Jaimes, RF, Giridhar, S, Kains, N, Kuppuswamy, K, Jørgensen, UG, Al-Subai, K, Andersen, JM, Bozza, V, Browne, P, Calchi Novati, S, Damerdji, Y, Diehl, C, Dominik, M, Dreizler, S, Elyiv, A, Giannini, E, Harpsøe, K, Hessman, FV, Hinse, TC, Hundertmark, M, Juncher, D, Kerins, E, Korhonen, H, Liebig, C, Mancini, L, Mathiasen, M, Penny, MT, Rabus, M, Rahvar, S, Ricci, D, Scarpetta, G, Skottfelt, J, Snodgrass, C, Southworth, J, Surdej, J, Tregloan-Reed, J, Vilela, C & Wertz, O 2013, 'A detailed census of variable stars in the globular cluster NGC 6333 (M9) from CCD differential photometry', Monthly Notices of the Royal Astronomical Society, vol. 434, no. 2, pp. 1220-1238. https://doi.org/10.1093/mnras/stt1080
Ferro, A. Arellano ; Bramich, D. M. ; Jaimes, R. Figuera ; Giridhar, Sunetra ; Kains, N. ; Kuppuswamy, K. ; Jørgensen, U. G. ; Al-Subai, Khalid ; Andersen, J. M. ; Bozza, V. ; Browne, P. ; Calchi Novati, S. ; Damerdji, Y. ; Diehl, C. ; Dominik, M. ; Dreizler, S. ; Elyiv, A. ; Giannini, E. ; Harpsøe, K. ; Hessman, F. V. ; Hinse, T. C. ; Hundertmark, M. ; Juncher, D. ; Kerins, E. ; Korhonen, H. ; Liebig, C. ; Mancini, L. ; Mathiasen, M. ; Penny, M. T. ; Rabus, M. ; Rahvar, S. ; Ricci, D. ; Scarpetta, G. ; Skottfelt, J. ; Snodgrass, C. ; Southworth, J. ; Surdej, J. ; Tregloan-Reed, J. ; Vilela, C. ; Wertz, O. / A detailed census of variable stars in the globular cluster NGC 6333 (M9) from CCD differential photometry. In: Monthly Notices of the Royal Astronomical Society. 2013 ; Vol. 434, No. 2. pp. 1220-1238.
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abstract = "We report CCD V and I time series photometry of the globular cluster NGC 6333 (M9). The technique of difference image analysis has been used, which enables photometric precision better than 0.05 mag for stars brighter than V ~ 19.0 mag, even in the crowded central regions of the cluster. The high photometric precision has resulted in the discovery of twonew RRc stars, three eclipsing binaries, seven long-term variables and one field RRab star behind the cluster. A detailed identification chart and equatorial coordinates are given for all the variable stars in the field of our images of the cluster. Our data together with the literature V-data obtained in 1994 and 1995 allowed us to refine considerably the periods for all RR Lyrae stars. The nature of the new variables is discussed. We argue that variable V12 is a cluster member and an Anomalous Cepheid. Secular period variations, doublemode pulsations and/or the Blazhko-like modulations in some RRc variables are addressed. Through the light-curve Fourier decomposition of 12 RR Lyrae stars we have calculated a mean metallicity of [Fe/H]ZW = -1.70 ± 0.01(statistical) ± 0.14(systematic) or [Fe/H]UVES = -1.67 ± 0.01(statistical) ± 0.19(systematic). Absolute magnitudes, radii and masses are also estimated for the RR Lyrae stars. A detailed search for SX Phe stars in the Blue Straggler region was conducted but none were discovered. If SX Phe exist in the cluster then their amplitudes must be smaller than the detection limit of our photometry. The colour-magnitude diagram has been corrected for heavy differential reddening using the detailed extinction map of the cluster of Alonso-Garc{\'i}a et al. This has allowed us to set the mean cluster distance from two independent estimates; from the RRab and RRc absolute magnitudes, we find 8.04 ± 0.19 and 7.88 ± 0.30 kpc, respectively.",
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author = "Ferro, {A. Arellano} and Bramich, {D. M.} and Jaimes, {R. Figuera} and Sunetra Giridhar and N. Kains and K. Kuppuswamy and J{\o}rgensen, {U. G.} and Khalid Al-Subai and Andersen, {J. M.} and V. Bozza and P. Browne and {Calchi Novati}, S. and Y. Damerdji and C. Diehl and M. Dominik and S. Dreizler and A. Elyiv and E. Giannini and K. Harps{\o}e and Hessman, {F. V.} and Hinse, {T. C.} and M. Hundertmark and D. Juncher and E. Kerins and H. Korhonen and C. Liebig and L. Mancini and M. Mathiasen and Penny, {M. T.} and M. Rabus and S. Rahvar and D. Ricci 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",
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TY - JOUR

T1 - A detailed census of variable stars in the globular cluster NGC 6333 (M9) from CCD differential photometry

AU - Ferro, A. Arellano

AU - Bramich, D. M.

AU - Jaimes, R. Figuera

AU - Giridhar, Sunetra

AU - Kains, N.

AU - Kuppuswamy, K.

AU - Jørgensen, U. G.

AU - Al-Subai, Khalid

AU - Andersen, J. M.

AU - Bozza, V.

AU - Browne, P.

AU - Calchi Novati, S.

AU - Damerdji, Y.

AU - Diehl, C.

AU - Dominik, M.

AU - Dreizler, S.

AU - Elyiv, A.

AU - Giannini, E.

AU - Harpsøe, K.

AU - Hessman, F. V.

AU - Hinse, T. C.

AU - Hundertmark, M.

AU - Juncher, D.

AU - Kerins, E.

AU - Korhonen, H.

AU - Liebig, C.

AU - Mancini, L.

AU - Mathiasen, M.

AU - Penny, M. T.

AU - Rabus, M.

AU - Rahvar, S.

AU - Ricci, D.

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.

PY - 2013/9/1

Y1 - 2013/9/1

N2 - We report CCD V and I time series photometry of the globular cluster NGC 6333 (M9). The technique of difference image analysis has been used, which enables photometric precision better than 0.05 mag for stars brighter than V ~ 19.0 mag, even in the crowded central regions of the cluster. The high photometric precision has resulted in the discovery of twonew RRc stars, three eclipsing binaries, seven long-term variables and one field RRab star behind the cluster. A detailed identification chart and equatorial coordinates are given for all the variable stars in the field of our images of the cluster. Our data together with the literature V-data obtained in 1994 and 1995 allowed us to refine considerably the periods for all RR Lyrae stars. The nature of the new variables is discussed. We argue that variable V12 is a cluster member and an Anomalous Cepheid. Secular period variations, doublemode pulsations and/or the Blazhko-like modulations in some RRc variables are addressed. Through the light-curve Fourier decomposition of 12 RR Lyrae stars we have calculated a mean metallicity of [Fe/H]ZW = -1.70 ± 0.01(statistical) ± 0.14(systematic) or [Fe/H]UVES = -1.67 ± 0.01(statistical) ± 0.19(systematic). Absolute magnitudes, radii and masses are also estimated for the RR Lyrae stars. A detailed search for SX Phe stars in the Blue Straggler region was conducted but none were discovered. If SX Phe exist in the cluster then their amplitudes must be smaller than the detection limit of our photometry. The colour-magnitude diagram has been corrected for heavy differential reddening using the detailed extinction map of the cluster of Alonso-García et al. This has allowed us to set the mean cluster distance from two independent estimates; from the RRab and RRc absolute magnitudes, we find 8.04 ± 0.19 and 7.88 ± 0.30 kpc, respectively.

AB - We report CCD V and I time series photometry of the globular cluster NGC 6333 (M9). The technique of difference image analysis has been used, which enables photometric precision better than 0.05 mag for stars brighter than V ~ 19.0 mag, even in the crowded central regions of the cluster. The high photometric precision has resulted in the discovery of twonew RRc stars, three eclipsing binaries, seven long-term variables and one field RRab star behind the cluster. A detailed identification chart and equatorial coordinates are given for all the variable stars in the field of our images of the cluster. Our data together with the literature V-data obtained in 1994 and 1995 allowed us to refine considerably the periods for all RR Lyrae stars. The nature of the new variables is discussed. We argue that variable V12 is a cluster member and an Anomalous Cepheid. Secular period variations, doublemode pulsations and/or the Blazhko-like modulations in some RRc variables are addressed. Through the light-curve Fourier decomposition of 12 RR Lyrae stars we have calculated a mean metallicity of [Fe/H]ZW = -1.70 ± 0.01(statistical) ± 0.14(systematic) or [Fe/H]UVES = -1.67 ± 0.01(statistical) ± 0.19(systematic). Absolute magnitudes, radii and masses are also estimated for the RR Lyrae stars. A detailed search for SX Phe stars in the Blue Straggler region was conducted but none were discovered. If SX Phe exist in the cluster then their amplitudes must be smaller than the detection limit of our photometry. The colour-magnitude diagram has been corrected for heavy differential reddening using the detailed extinction map of the cluster of Alonso-García et al. This has allowed us to set the mean cluster distance from two independent estimates; from the RRab and RRc absolute magnitudes, we find 8.04 ± 0.19 and 7.88 ± 0.30 kpc, respectively.

KW - Globular clusters: individual: NGC 6333

KW - Stars: fundamental parameters

KW - Stars: variables: general

KW - Stars: variables: RR Lyrae

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DO - 10.1093/mnras/stt1080

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