J/other/IJAA/15.ivo://CDS.VizieR/J/other/IJAA/15.171CDSPaiz L.G.De Biasi M.S.Orellana R.B.Corti M.A.2025-10-01T06:29:29Z2025-09-12T08:35:46ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyopen-star-clustersstellar-associationsearly-type-starsvisible-astronomyWe revisit the Cygnus OB2 region to perform a detailed open cluster census taking profit from the high accuracy of Gaia DR3 astrometric and photometric data. HDBSCAN clustering algorithm is applied to the five astrometric parameters (RA,DE,pmRA*cosDE,pmDE,Plx) in a circular region centred at (l,b)=(79.8{deg},+0.8{deg}) of radius 1.5{deg} up to G=19.5mag and leads us to detect four unnoticed open clusters named RSL-03, RSL-04, RSL-05 and RSL-06, as well as 20 known clusters. The mean proper motion of the open clusters is determined and the members are identified. The coordinates of the centre of the clusters and radii are calculated and their distances are estimated. The analysis of the mean proper motion and the distance of Bica 1, Bica 2, FSR 0236, FSR 0238, FSR 0224, HSC 625, OC-123, OC-128, NGC 6910, RSL-04, RSL-05, and RSL-06 suggests that these open clusters would be related to Cyg OB2 association. This is the first time that Bica 1 and Bica 2 have been identified using the Gaia DR3 five astrometric parameters. Besides, the open cluster HSC 630 would be related to the Left over-density found by our working group in a previous paper as an association candidate.2025IJAA...15..171Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/other/IJAA/15.171CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/A+A/686/A42 : Improving the open cluster census. III. (Hunt+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/other/IJAA/15.171https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/other/IJAA/15.171http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/other/IJAA/15.171https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/other/IJAA/15.171https://vizier.iucaa.in/viz-bin/votable?-source=J/other/IJAA/15.171http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/other/IJAA/15.171GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/other/IJAA/15.171/table3 (Cluster parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/other/IJAA/15.171/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/other/IJAA/15.171/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/other/IJAA/15.171/table3?GETtext/xml+votable180.050000true306.10142.2520.005555555555555556Cone search capability for table J/other/IJAA/15.171/members (Gaia DR3 parameters of astrometric members of all open clusters studied)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/other/IJAA/15.171/members?https://vizier.iucaa.in/viz-bin/conesearch/J/other/IJAA/15.171/members?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/other/IJAA/15.171/members?GETtext/xml+votable180.050000true306.0939216404642.266534671470.0055555555555555565/3672 6/14667 14670 14692-14694 14696-14697 14700https://cdsarc.cds.unistra.fr/viz-bin/moc/J/other/IJAA/15.171?format=asciiOpticaldefaultJ/other/IJAA/15.171/table3Cluster parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterOpen clustermeta.id;meta.maincharn_Cluster[*] Note on Cluster (1)meta.notecharRA_ICRSCluster centre right ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSCluster centre declination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainpmRAcosDECluster mean proper motion in right ascension multiplied by cos(dec)mas/yrpos.pm;pos.eq.rafloate_pmRAcosDEStandard error of pmRAcosDEmas/yrstat.error;pos.pm;pos.eq.rafloatpmDECluster mean proper motion in declinationmas/yrpos.pm;pos.eq.decfloate_pmDEStandard error of pmDEmas/yrstat.error;pos.pm;pos.eq.decfloat_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.decindexedNcNumber of membersmeta.numberintNhp? Number of highly probable membersmeta.numberintnullablercRadiusarcminphys.angSize;srcfloatplxMean parallaxmaspos.parallax.trigfloate_plxStandard error of plxmasstat.error;pos.parallaxfloatDistEstimated distancepcpos.distanceinte_DistStandard error of Distpcstat.errorintJ/other/IJAA/15.171/membersGaia DR3 parameters of astrometric members of all open clusters studied_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.decindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterOpen cluster namemeta.id.parentcharRA_ICRSRight ascension of star (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRSDeclination of star (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainGaiaDR3Gaia DR3 source IDmeta.id;meta.mainplxMean parallaxmaspos.parallax.trigfloate_plxStandard error of parallaxmasstat.error;pos.parallaxfloatpmRAcosDEMean proper motion in right ascension multiplied by cos(dec)mas/yrpos.pm;pos.eq.rafloate_pmRAcosDEStandard error of pmRAcosDEmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEMean proper motion in declinationmas/yrpos.pm;pos.eq.decfloate_pmDEStandard error of pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatGmagMean G-band magnitudemagphot.mag;em.optdouble