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arXiv · 1901.04733

Age determination for 269 $Gaia$ DR2 Open Clusters

D. Bossini·A. Vallenari·A. Bragaglia·T. Cantat-Gaudin·R. Sordo·L. Balaguer-Núñez·C. Jordi·A. Moitinho·C. Soubiran·L. Casamiquela·R. Carrera·U. Heiter
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Abstract

$Context$. Gaia Second Data Release provides precise astrometry and photometry for more than 1.3 billion sources. This catalog opens a new era concerning the characterization of open clusters and test stellar models, paving the way for a better understanding of the disc properties. $Aims$. The aim of the paper is to improve the knowledge of cluster parameters, using only the unprecedented quality of the Gaia photometry and astrometry. $Methods$. We make use of the membership determination based on the precise Gaia astrometry and photometry. We apply anautomated Bayesian tool, BASE-9, to fit stellar isochrones on the observed G, GBP, GRP magnitudes of the high probability member stars. $Results$. We derive parameters such as age, distance modulus and extinction for a sample of 269 open clusters, selecting only low reddening objects and discarding very young clusters, for which techniques other than isochrone-fitting are more suitable for estimating ages.

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D. Bossini, A. Vallenari, A. Bragaglia, T. Cantat-Gaudin, R. Sordo, L. Balaguer-Núñez, C. Jordi, A. Moitinho, C. Soubiran, L. Casamiquela, R. Carrera, U. Heiter. 2019-01-15. Age determination for 269 $Gaia$ DR2 Open Clusters. https://doi.org/10.1051/0004-6361%2F201834693

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