J/other/NewA/49.50 New Variables in 3 Galactic open clusters (Palma+, 2016)
New variable stars discovered in the fields of three Galactic open clusters
using the VVV survey.
Palma T., Minniti D., Dekany I., Claria J.J., Alonso-Garcia J.,
Gramajo L.V., Ramirez Alegria S., Bonatto C.
<New Astron., 49, 50-62 (2016)>
=2016NewA...49...50P 2016NewA...49...50P (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, variable ; Photometry, infrared
Keywords: Galaxy; stellar content -
open clusters and associations; individual;
antalova 1; ASCC 90; ESO 393-15 - stars: variables: General
Abstract:
This project is a massive near-infrared (NIR) search for variable
stars in highly reddened and obscured open cluster (OC) fields
projected on regions of the Galactic bulge and disk. The search is
performed using photometric NIR data in the J-, H- and Ks - bands
obtained from the Vista Variables in the Via Lactea (VVV) Survey. We
performed in each cluster field a variability search using Stetson's
variability statistics to select the variable candidates. Later, those
candidates were subjected to a frequency analysis using the
Generalized Lomb-Scargle and the Phase Dispersion Minimization
algorithms. The number of independent observations range between 63
and 73. The newly discovered variables in this study, 157 in total in
three different known OCs, are classified based on their light curve
shapes, periods, amplitudes and their location in the corresponding
color-magnitude (J-Ks,Ks)(J-Ks,Ks) and color-color
(H-Ks,J-H)(H-Ks,J-H) diagrams. We found 5 possible Cepheid
stars which, based on the period-luminosity relation, are very likely
type II Cepheids located behind the bulge. Among the newly discovered
variables, there are eclipsing binaries, δ Scuti, as well as
background RR Lyrae stars. Using the new version of the Wilson &
Devinney code as well as the "Physics Of Eclipsing Binaries"
(PHOEBE) code, we analyzed some of the best eclipsing binaries we
discovered. Our results show that these studied systems turn out to be
ranging from detached to double-contact binaries, with low
eccentricities and high inclinations of approximately 80°. Their
surface temperatures range between 3500K and 8000K.
Description:
The observations were made as part of the VVV Survey.
For each cluster field, we extracted and analyzed VVV data for objects
that best matched the positions of previously reported variable stars
(Zejda et al., 2012, Cat. J/A+A/548/A97), and also performed a blind
variability search.
Objects:
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RA (2000) DE Designation(s)
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17 28 57.0 -31 34 48 Cl Antalova 1 = Cl Antalova 1
17 39 07.2 -34 48 54 ASCC 90 = [KPR2005] 90
17 43 35.3 -34 13 38 ESO 393-15 = ESO 393-15
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 92 58 List of variable stars found in Antalova 1
table4.dat 93 81 List of variable stars found in ASCC 90
table5.dat 92 18 List of variable stars found in ESO 393-15
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See also:
J/A+A/548/A97 : Catalogue of variable stars in open clusters (Zejda+, 2012)
Byte-by-byte Description of file: table3.dat table4.dat table5.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- VName Variable name within the open cluster
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 15 F5.2 s RAs Right ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 27 F4.1 arcsec DEs Declination (J2000)
29- 33 F5.2 arcmin Dist ?=- Distance to the cluster center
35- 42 F8.5 d Per ?=- Period
44- 48 F5.3 mag Amp Ks total amplitude
50- 54 F5.2 mag <Ksmag> Mean Ks magnitude
56- 59 F4.2 mag J-Ks ?=- J-Ks colour index
61- 64 F4.2 mag H-Ks ?=- H-Ks colour index
66- 77 A12 --- Class Classification
79- 93 A15 --- Com Comments (other types/periods)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 15-Dec-2016