Washington photometry of open cluster giants: Two moderately metal-poor anticentre clusters

New photometric data in the Washington system are presented for red giant candidates in NGC 1817 and 2251, two open clusters located towards the Galactic anticentre direction. In the case of NGC 2251, the Washington data are supplemented with new UBV and David Dunlap Observatory (DDO) photoelectric...

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Detalles Bibliográficos
Publicado: 2005
Materias:
Galaxy: abundances
Methods: observational
Open clusters and associations: individual: NGC 1817
Open clusters and associations: individual: NGC 2251
Techniques: photometric
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00358711_v363_n4_p1247_Parisi
http://hdl.handle.net/20.500.12110/paper_00358711_v363_n4_p1247_Parisi
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00358711_v363_n4_p1247_Parisi
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spelling paper:paper_00358711_v363_n4_p1247_Parisi2023-06-08T15:01:20Z Washington photometry of open cluster giants: Two moderately metal-poor anticentre clusters Galaxy: abundances Methods: observational Open clusters and associations: individual: NGC 1817 Open clusters and associations: individual: NGC 2251 Techniques: photometric New photometric data in the Washington system are presented for red giant candidates in NGC 1817 and 2251, two open clusters located towards the Galactic anticentre direction. In the case of NGC 2251, the Washington data are supplemented with new UBV and David Dunlap Observatory (DDO) photoelectric photometry. Published radial velocities are used to separate field stars from cluster giants. The photometric data yield an effective temperature and metal abundance for each cluster member. Five independent Washington abundance indices yield mean metallicities of [Fe/H] = 0.25 ± 0.04 for NGC 1817 and 2251, respectively. From combined BV and DDO data, we also derive E(B -V) = 0.21 ± 0.03 and [Fe/H]DDO = -0.14 ± 0.05 for NGC 2251. Both objects are then found to be on the metal-poor side of the distribution of open clusters, their metallicities being compatible with the existence of a radial abundance gradient in the disc. Using the WEBDA Open Cluster data base and the available literature, we re-examined the overall properties of a sample of 30 clusters located towards the Galactic anticentre with the distances, ages and metallicities available. This cluster sample presents no evidence of an abundance gradient perpendicular to the Galactic plane, nor is an age-metallicity relation found. However, a radial abundance gradient of -0.093 dex kpc-1 is derived over a Galactocentric distance of 14 kpc, a gradient which is in keeping with most recent determinations. This value practically does not change when all clusters with basic parameters known up to this date are considered. © 2005 RAS. 2005 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00358711_v363_n4_p1247_Parisi http://hdl.handle.net/20.500.12110/paper_00358711_v363_n4_p1247_Parisi
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Galaxy: abundances
Methods: observational
Open clusters and associations: individual: NGC 1817
Open clusters and associations: individual: NGC 2251
Techniques: photometric
spellingShingle Galaxy: abundances
Methods: observational
Open clusters and associations: individual: NGC 1817
Open clusters and associations: individual: NGC 2251
Techniques: photometric
Washington photometry of open cluster giants: Two moderately metal-poor anticentre clusters
topic_facet Galaxy: abundances
Methods: observational
Open clusters and associations: individual: NGC 1817
Open clusters and associations: individual: NGC 2251
Techniques: photometric
description New photometric data in the Washington system are presented for red giant candidates in NGC 1817 and 2251, two open clusters located towards the Galactic anticentre direction. In the case of NGC 2251, the Washington data are supplemented with new UBV and David Dunlap Observatory (DDO) photoelectric photometry. Published radial velocities are used to separate field stars from cluster giants. The photometric data yield an effective temperature and metal abundance for each cluster member. Five independent Washington abundance indices yield mean metallicities of [Fe/H] = 0.25 ± 0.04 for NGC 1817 and 2251, respectively. From combined BV and DDO data, we also derive E(B -V) = 0.21 ± 0.03 and [Fe/H]DDO = -0.14 ± 0.05 for NGC 2251. Both objects are then found to be on the metal-poor side of the distribution of open clusters, their metallicities being compatible with the existence of a radial abundance gradient in the disc. Using the WEBDA Open Cluster data base and the available literature, we re-examined the overall properties of a sample of 30 clusters located towards the Galactic anticentre with the distances, ages and metallicities available. This cluster sample presents no evidence of an abundance gradient perpendicular to the Galactic plane, nor is an age-metallicity relation found. However, a radial abundance gradient of -0.093 dex kpc-1 is derived over a Galactocentric distance of 14 kpc, a gradient which is in keeping with most recent determinations. This value practically does not change when all clusters with basic parameters known up to this date are considered. © 2005 RAS.
title Washington photometry of open cluster giants: Two moderately metal-poor anticentre clusters
title_short Washington photometry of open cluster giants: Two moderately metal-poor anticentre clusters
title_full Washington photometry of open cluster giants: Two moderately metal-poor anticentre clusters
title_fullStr Washington photometry of open cluster giants: Two moderately metal-poor anticentre clusters
title_full_unstemmed Washington photometry of open cluster giants: Two moderately metal-poor anticentre clusters
title_sort washington photometry of open cluster giants: two moderately metal-poor anticentre clusters
publishDate 2005
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00358711_v363_n4_p1247_Parisi
http://hdl.handle.net/20.500.12110/paper_00358711_v363_n4_p1247_Parisi
_version_ 1768545918304387072

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