J/other/RMxAA/60.381 NGC 1851 variables light curves (Arellano Ferro+, 2024)
The variable stars population of the extended young globular cluster NGC 1851.
Arellano Ferro A., Perez Parra C.E., Yepez M.A., Bustos Fierro I.H.,
Prudil Z., Zerpa Guillen L.J.
<Rev. Mex. Astron. Astrofis., 60, 381-396 (2024)>
=2024RMxAA..60..381A 2024RMxAA..60..381A (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, globular ; Stars, variable ; Photometry ; Optical
Keywords: star: globular clusters: general -
globular clusters: individual (NGC 1851) - stars: horizontal branch -
stars: distances - stars: fundamental parameters -
stars: variables: RR Lyrae
Abstract:
We report VI CCD photometry of the globular cluster cluster NGC 1851.
We aim to study the membership of the variable stars detected in the
field of the cluster as listed in the Catalogue of Variable stars in
Globular Clusters (CVSGC; Clement et al., 2001AJ....122.2587C 2001AJ....122.2587C, Cat.
V/150) and reported by the Gaia mission. We cross match the two sets
of variables to produce light curves that lead to the estimation of
physical parameters. The resulting colour-magnitude diagram (CMD),
free of likely field stars, enables to confirm the position of the
variables, their type and evolutionary stage. We provide new
estimations of the period using data acquired on a long time- base.
The Fourier decomposition of cluster member RR Lyrae light curves lead
to a mean metallicity and distance of [Fe/H]ZW=-1.35±0.22dex and
11.9±0.6kpc. The variability and membership of stars reported by
Gaia-DR3 as variables in the field of the cluster is discussed.
Description:
The data used in this work were obtained at the Bosque Alegre
Astronomical Station (EABA), of the National Observatory of Cordoba,
Argentina during August-September 2018 and between June and August
2019. Two different detectors were used; a CCD KAF-16803 (2018) and
CCD KAF-6303E (2019 covering a field of 16.9x16.9arcmin2 and
12.6x8.4arcmin2 respectively. The data reductions were carried out
with the DanDIA pipeline (Bramich, 2008MNRAS.386L..77B 2008MNRAS.386L..77B; Bramich et
al., 2013MNRAS.428.2275B 2013MNRAS.428.2275B). A membership analysis was performed using
the Gaia-DR3 proper motions and our V and I time-series CCD photometry
was employed to produce a clean color-magnitude diagram and to study
the variable stars in the cluster. Numerous reported variables in the
field of view of the cluster were identified as non-members. Member
RR LYraes were used to estimate the metallicity and distance of the
cluster via the light curve Fourier decomposition.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 122 80 General data of variables in the field of
NGC 18511
table2.dat 50 25518 VI photometry of 62 variables in the field of
NGC 6558
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See also:
J/MNRAS/488/3024 : Globular clusters members with Gaia DR2
(Bustos Fierro+, 2019)
J/MNRAS/505/5978 : Gaia EDR3 view on Galactic globular clusters
(Vasiliev+, 2021)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- VName Variable name, VNN
5- 7 A3 ---- OName Other name, for variables identifier in Gaia
9- 15 A7 --- VType Variable type
17- 22 F6.3 mag <Vmag> ?=- Intensity weighted mean V magnitude
23 A1 --- n_<Vmag> [*] V magnitude weighted mean in <Vmag>
24- 29 F6.3 mag <Imag> ?=- Intensity weighted mean I magnitude
30 A1 --- n_<Imag> [*] I magnitude weighted mean in <Imag>
31- 35 F5.3 mag AV ?=- Amplitude of variation in V band
37- 41 F5.3 mag AI ?=- Amplitude of variation in I band
43- 50 F8.6 d Per ?=- Period
52- 60 F9.4 d HJDmax ?=- Maximum brightness HJD (HJD-2450000)
62- 63 A2 --- MembB+C Membership status found in this work from the
method of Bustos Fierro & Calderon
(2019MNRAS.488.3024B 2019MNRAS.488.3024B, Cat. J/MNRAS/488/3024)
(1)
65- 68 F4.2 --- MembV+B ? Membership probability assigned by
Vasiliev & Baumgardt (2021MNRAS.505.5978V 2021MNRAS.505.5978V,
Cat. J/MNRAS/505/5978)
70- 73 A4 --- Memb ? Membership code (2)
75- 76 I2 h RAh Right ascension (J2000.0)
78- 79 I2 min RAm Right ascension (J2000.0)
81- 85 F5.2 s RAs Right ascension (J2000.0)
87 A1 --- DE- Declination sign (J2000.0)
88- 89 I2 deg DEd Declination (J2000.0)
91- 92 I2 arcmin DEm Declination (J2000.0)
94- 97 F4.1 arcsec DEs Declination (J2000.0)
99-102 A4 --- Status [New NewG GNC] Status (3)
104-122 I19 --- GaiaDR3 ? Gaia DR3 identifier for variables in Gaia-DR3
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Note (1): Membership code as follows:
M1 = likely member
M2 = likely member
UN = unknown
FS = field stars
Note (2): Membership code as follows:
m = member
f = field star
Note (3): Code as follows:
New = new star identified in the NGC1851 field
NewG = variables in Gaia-DR3 confirmed in the present work
GNC = Variables in Gaia-DR3 not confirmed in the present work
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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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2- 4 A3 --- VName Variable name, VNN
10 A1 --- Filter [VI] Observation filter
15- 27 F13.5 d HJD Heliocentric Julian date
30- 35 F6.3 mag magst Standard magnitude
38- 43 F6.3 mag maginst Instrumental magnitude
46- 50 F5.3 mag e_maginst Error on the magnitude
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Acknowledgements:
Armando Arellano Ferro, armando(at)astro.unam.mx
(End) A. Arelano Ferro [IA-UNAM, Mexico], P. Vannier [CDS] 22-Oct-2024