J/A+A/677/A163ivo://CDS.VizieR/J/A+A/677/A163doi:10.26093/cds/vizier.36770163CDSAlfonso J.Garcia-Varela A.2025-07-03T20:00:55Z2023-09-21T09:25:21ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frmilky-way-galaxyopen-star-clustersastrometryvisible-astronomyNearby open clusters, such as Pleiades, Praesepe, and Blanco 1, have been extensively studied due to their proximity to the Sun. The Gaia data provide the opportunity to investigate these clusters, because they contain valuable astrometric and photometric information that can be used to update their kinematic and stellar properties. Our goal is to carry out a star membership study in these nearby open clusters by employing an astrometric model with proper motions (PMs) and an unsupervised clustering machine learning algorithm that uses positions, PMs, and parallaxes. The star members are selected from the cross-matching between both methods. Once we know the members, we investigate the spatial distributions of these clusters and estimate their distances, ages, and metallicities. We used the Gaia DR3 catalogue to determine star members using two approaches: a classical Bayesian model and the unsupervised machine learning algorithm DBSCAN. For star members, we built radial density profiles and spatial distributions, and computed the King parameters. The ages and metallicities were estimated using the BASE-9 Bayesian software. Results: We identified 958, 744, and 488 star members for Pleiades, Praesepe, and Blanco 1, respectively. We corrected the distances and built the spatial distributions, finding that Praesepe and Blanco 1 have elongated shape structures. The distances, ages, and metallicities obtained were consistent with those reported in the literature. We obtained catalogues of star members, and updated kinematic and stellar parameters for these open clusters. We find that the PMs model can find a similar number of members to the unsupervised clustering algorithm when the cluster population forms an overdensity in the vector point diagram. This allows us to select an adequate size of the PMs region with which to run these methods. Our analysis found stars that are being directed towards the outskirts of Praesepe and Blanco 1, which exhibit elongated shapes. These stars have high membership probabilities and similar PMs to those within the tidal radius.2023A&A...677A.163Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/677/A163CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/677/A163https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/677/A163http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/677/A163https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/677/A163https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/677/A163http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/677/A163GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/677/A163/members (Members of the open clusters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/677/A163/members?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/677/A163/members?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/677/A163/members?GETtext/xml+votable180.050000true55.7739824907221.03021972560.0055555555555555565/113-116 118 120-121 123-124 126 1171 1174-1175 1177 1180 4111 4120 4122 4135 4144 6/365-367 376 378-379 382 413 437 449-451 468 470 476 478-479 489 500 509 511 848-849 851 4675 4677-4679 4681 4683 4690-4691 4694-4695 4705 4716-4717 4724-4726 4728-4729 4732 4896 16439 16486-16487 16492 16494 16533 16535 16580 16582 16584-16586 16608https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/677/A163?format=asciiOpticaldefaultJ/A+A/677/A163/membersMembers of the open clustersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Gaia DR3 source IDmeta.id;meta.mainRA_ICRSRight Ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainPlxAbsolute stellar parallaxmaspos.parallaxdoublepmRAProper motion in right ascension directionmas/yrpos.pm;pos.eq.radoublepmDEProper motion in declination directionmas/yrpos.pm;pos.eq.decdoubleClusterCluster namemeta.id.parentcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.raindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decindexed