J/MNRAS/434/1220 Vi light curves of NGC6333 variables (Arellano Ferro+, 2013)
A detailed census of variable stars in the globular cluster NGC 6333 (M9) from
CCD differential photometry.
Arellano Ferro A., Bramich D.M., Figuera Jaimes R., Giridhar S., Kains N.,
Kuppuswamy K., Jorgensen U.G., Alsubai K.A., Andersen J.M., Bozza V.,
Browne P., Calchi Novati S., Damerdji Y., Diehl C., Dominik M., Dreizler S.,
Elyiv A., Giannini E., Harpsoe 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.
<Mon. Not. R. Astron. Soc. 434, 1220 (2013)>
=2013MNRAS.434.1220A 2013MNRAS.434.1220A
ADC_Keywords: Clusters, globular ; Stars, variable ; Photometry, CCD
Keywords: stars: variables: general - stars: variable: RR Lyrae -
globular clusters: individual: NGC 6333
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 0.05mag for
stars brighter than V∼19.0mag, even in the crowded central regions
of the cluster. The high photometric precision has resulted in the
discovery of two new 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, double-mode 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-Garcia et al. (2012, Cat. J/AJ/143/70). 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±0.30kpc, respectively.
Description:
V and i time-series photometry for all confirmed variables in
NGC 6333.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 107 34 *General data for all of the confirmed variables
in NGC 6333 in the FOV of our images.
table2.dat 89 14438 V and i light curves
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Note on table3.dat: Stars V22-V34 are new discoveries in this work.
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See also:
J/AJ/89/1707 : Photographic observations of M9 variable stars (Clement+, 1984)
J/AJ/112/618 : CCD photometry of variable stars in M9 (Clement+, 1996)
J/AJ/101/1352 : Observations of variable stars in M9 (Clement+, 1991)
J/AJ/118/453 : M9 RR Lyrae CCD observations (Clement+, 1999)
J/AJ/143/70 : Differential reddening in Milky Way globulars
(Alonso-Garcia+, 2012)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- VName Variable name (V1 to V34, V22-V34 are new),
<Cl* NGC 6333 SAW VNN> in Simbad
5- 11 A7 --- VType Variable type (1)
12 A1 --- n_VType [c] c: Possibly EA
14- 19 F6.3 mag <Vmag> Average V magnitude
21- 26 F6.3 mag ?=- Average i magnitude
28 A1 --- l_AV Limit flag on AV
29- 33 F5.3 mag AV Amplitude in V band
34 A1 --- n_AV [b] b: Depth of eclipse
36 A1 --- l_Ai Limit flag on Ai
37- 41 F5.3 mag Ai ?=- Amplitude in i band
42 A1 --- n_Ai [b] b: Ai lists the depth of eclipse
45- 53 F9.7 d Per ? Period, from this work
54 A1 --- n_Per [d] d: the real period may be twice this value
56- 60 F5.2 d/Myr beta ? Secular period change β=dP/dt
62- 70 F9.4 d HJDmax ?=- Time of maximum eclipse (HJD-2450000)
71 A1 --- n_HJDmax [a] a: Time of minimum light
72- 82 F11.7 d Per1 ?=- Period from Clements papers (2)
85- 86 I2 h RAh Right ascension (J2000)
88- 89 I2 min RAm Right ascension (J2000)
91- 95 F5.2 s RAs Right ascension (J2000)
97 A1 --- DE- Declination sign (J2000)
98- 99 I2 deg DEd Declination (J2000)
101-102 I2 arcmin DEm Declination (J2000)
104-107 F4.1 arcsec DEs Declination (J2000)
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Note (1): Labels 'Bl' and 'd' are for Blazhko variables and double-mode
RR Lyrae, respectively; 'An.Cep' stands for Anomalous Cepheid,
'E' for Eclising binary (possibly EA), 'EW' for contact eclipsing
binaries (W UMa-type), 'LPV' for Long-Period Variable.
Note (2): The best previous period estimates for each variable from the Clement
series of papers (Clement et al., 1984, Cat. J/AJ/89/1707;
Clement & Walker 1991, Cat. J/AJ/101/1352;
Clement & Shelton 1996, Cat. J/AJ/112/618, 1999, Cat. J/AJ/118/453)
are reported for comparison with our refined periods.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- VName Variable name, VNN
5- 9 A5 --- Tel [2.0H 1.5LS] Telescope: 2.0H=2m telescope in
Hanle; 1.5LS=1.54m telescope in La Silla, ESO.
11 A1 --- Fltr [VI] Observation filter (V or I)
13- 25 F13.5 d HJD Heliocentric Julian date
27- 32 F6.3 mag magst Standard magnitude
34- 39 F6.3 mag mag Instrumental magnitude
41- 45 F5.3 mag e_mag Error on the magnitude
47- 56 F10.3 s-1 Fref Reference flux (in ADU/s)
58- 63 F6.3 s-1 e_Fref Error on the reference flux (in ADU/s)
65- 74 F10.3 s-1 DFlux Differential flux (in ADU/s)
76- 82 F7.3 s-1 e_DFlux Error on the differential flux (in ADU/s)
84- 89 F6.4 --- p [0.3/1.4] Photometric scale factor
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Acknowledgements:
Daniel Bramich, dbramich(at)eso.org
Roberto Figuera, rfiguera(at)eso.org
(End) Daniel Bramich [ESO], Patricia Vannier [CDS] 15-Oct-2013