The variable star population in the globular cluster NGC 6934

Abstract We report an analysis of new V and I CCD time-series photometry of the globular cluster NGC 6934. Through the Fourier decomposition of the RR Lyrae light curves the mean values of [Fe/H] and the distance of the cluster were estimated; we found: [Fe/H]UV ES=−1.48±0.14 and d=16.03 ± 0.42 kpc, and [Fe/H]UV ES=−1.43±0.11 and d=15.91±0.39 kpc, from the calibrations of RRab and RRc stars respectively. Independent distance estimations from SX Phe and SR stars are also discussed. Individual absolute magnitudes, radii and masses are also reported for RR Lyrae stars. We found 12 new variables: 4 RRab, 3 SX Phe, 2 W Virginis (CW) and 3 semi-regular (SR). The inter-mode or “either-or” region in the instability strip is shared by the RRab and RRc stars. This characteristic, observed only in some OoI clusters and never seen in an OoII, is discussed in terms of mass distribution in the ZAHB.

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Main Authors: Yepez,M. A., Arellano Ferro,A., Muneer,S., Giridhar,Sunetra
Format: Digital revista
Language:English
Published: Universidad Nacional Autónoma de México, Instituto de Astronomía 2018
Online Access:http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0185-11012018000100002
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spelling oai:scielo:S0185-110120180001000022019-08-05The variable star population in the globular cluster NGC 6934Yepez,M. A.Arellano Ferro,A.Muneer,S.Giridhar,Sunetra globular clusters individual NGC 6934 stars variables RR Lyrae Abstract We report an analysis of new V and I CCD time-series photometry of the globular cluster NGC 6934. Through the Fourier decomposition of the RR Lyrae light curves the mean values of [Fe/H] and the distance of the cluster were estimated; we found: [Fe/H]UV ES=−1.48±0.14 and d=16.03 ± 0.42 kpc, and [Fe/H]UV ES=−1.43±0.11 and d=15.91±0.39 kpc, from the calibrations of RRab and RRc stars respectively. Independent distance estimations from SX Phe and SR stars are also discussed. Individual absolute magnitudes, radii and masses are also reported for RR Lyrae stars. We found 12 new variables: 4 RRab, 3 SX Phe, 2 W Virginis (CW) and 3 semi-regular (SR). The inter-mode or “either-or” region in the instability strip is shared by the RRab and RRc stars. This characteristic, observed only in some OoI clusters and never seen in an OoII, is discussed in terms of mass distribution in the ZAHB.info:eu-repo/semantics/openAccessUniversidad Nacional Autónoma de México, Instituto de AstronomíaRevista mexicana de astronomía y astrofísica v.54 n.1 20182018-01-01info:eu-repo/semantics/articletext/htmlhttp://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0185-11012018000100002en
institution SCIELO
collection OJS
country México
countrycode MX
component Revista
access En linea
databasecode rev-scielo-mx
tag revista
region America del Norte
libraryname SciELO
language English
format Digital
author Yepez,M. A.
Arellano Ferro,A.
Muneer,S.
Giridhar,Sunetra
spellingShingle Yepez,M. A.
Arellano Ferro,A.
Muneer,S.
Giridhar,Sunetra
The variable star population in the globular cluster NGC 6934
author_facet Yepez,M. A.
Arellano Ferro,A.
Muneer,S.
Giridhar,Sunetra
author_sort Yepez,M. A.
title The variable star population in the globular cluster NGC 6934
title_short The variable star population in the globular cluster NGC 6934
title_full The variable star population in the globular cluster NGC 6934
title_fullStr The variable star population in the globular cluster NGC 6934
title_full_unstemmed The variable star population in the globular cluster NGC 6934
title_sort variable star population in the globular cluster ngc 6934
description Abstract We report an analysis of new V and I CCD time-series photometry of the globular cluster NGC 6934. Through the Fourier decomposition of the RR Lyrae light curves the mean values of [Fe/H] and the distance of the cluster were estimated; we found: [Fe/H]UV ES=−1.48±0.14 and d=16.03 ± 0.42 kpc, and [Fe/H]UV ES=−1.43±0.11 and d=15.91±0.39 kpc, from the calibrations of RRab and RRc stars respectively. Independent distance estimations from SX Phe and SR stars are also discussed. Individual absolute magnitudes, radii and masses are also reported for RR Lyrae stars. We found 12 new variables: 4 RRab, 3 SX Phe, 2 W Virginis (CW) and 3 semi-regular (SR). The inter-mode or “either-or” region in the instability strip is shared by the RRab and RRc stars. This characteristic, observed only in some OoI clusters and never seen in an OoII, is discussed in terms of mass distribution in the ZAHB.
publisher Universidad Nacional Autónoma de México, Instituto de Astronomía
publishDate 2018
url http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S0185-11012018000100002
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