J/A+A/697/A47ivo://CDS.VizieR/J/A+A/697/A47doi:10.26093/cds/vizier.36970047CDSQuintana A.L.Negueruela I.Berlanas S.R.2025-09-22T20:01:28Z2025-05-06T10:39:55ZCDS support team

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

cds-question@unistra.frmilky-way-galaxygalaxy-planesopen-star-clustersstellar-agesob-starseffective-temperaturestellar-distanceCas OB5 is an OB association located at a distance of 2.5-3kpc that intercepts the Perseus spiral arm. It carries a moderate amount of reddening (A_V_~2-3mag) and contains several well-known open clusters within its boundaries, such as King 12, NGC 7788, and NGC 7790. The availability of modern clustering algorithms, together with Gaia DR3 kinematics and complementary spectroscopic data, makes it a suitable site for studies of Galactic structure. We seek to quantify the spatial scale of star formation in the spiral arms, using Cas OB5 as a pilot target before extending our study to more distant and extinguished regions of the Galaxy. We selected 129,695 candidate OBA stars in a 6x8deg^2^ region around Cas OB5. We applied a spectral energy distribution (SED) fitting process to this sample to derive the physical parameters. Through this process, we found 56379 OBA stars, which we then clustered using HDBSCAN. We identified 17 open clusters inside this area, four of which appear to form a coherent structure that we identify as Cas OB5. Nevertheless, our findings suggest that these clusters belong to two different age groups despite sharing a similar position and kinematics. Spectroscopic observations confirm the youth of NGC 7788 (10-15Myr) compared to NGC 7790 (110+/-15Myr). We have determined a spatial scale for star formation of a few tens of pc to a few hundreds of pc, comparing the clustered to the diffuse population of Cas OB5 across this part of the Perseus arm. A spectroscopic analysis was required to complement the clustering algorithm, so that we could separate younger OCs (tracers of the spiral arm) from older ones. These results highlight the need to combine these techniques to fully disentangle the Milky Way structure.2025A&A...697A..47Qhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/697/A47CatalogResearchIsServedByTAP 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/697/A47https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/697/A47http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/697/A47https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/697/A47https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/697/A47http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/697/A47GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/697/A47/catalog (Catalog of 56379 SED-fitted OBA stars around Cas OB5 with cluster properties and membership)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/697/A47/catalog?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/697/A47/catalog?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/697/A47/catalog?GETtext/xml+votable180.050000true358.6935899262.788638640.0055555555555555564/190 5/751 766-767 938 3551 3573 3575 3581 3583 3924 6/2999 3003 3058-3059 3062-3063 3746-3747 3756 14198-14199 14203 14289 14291 14297 14299 14321 14323 14329-14331 15700-15702https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/697/A47?format=asciidefaultJ/A+A/697/A47/catalogCatalog of 56379 SED-fitted OBA stars around Cas OB5 with cluster properties and membership_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.recordintGaiaDR3Gaia DR3 source identifiermeta.id;meta.mainRA_ICRSBarycentric right ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainindexede_RA_ICRSError on barycentric right ascension (ICRS)degstat.error;pos.eq.radoubleDE_ICRSBarycentric declination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainindexede_DE_ICRSError on barycentric declination (ICRS)degstat.error;pos.eq.decdoubleGLONGalactic longitude of the sourcedegpos.galactic.lonGLATGalactic latitude of the sourcedegpos.galactic.latdoubleplxGaia DR3 corrected parallaxmaspos.parallax.trigdoublee_plxGaia DR3 corrected parallax uncertaintymasstat.error;pos.parallaxdoublepmRAProper motion in right ascension, pmRA*cosDE, of the source (ICRS) at Ep=2016.0mas/yrpos.pm;pos.eq.rafloate_pmRAStandard error of proper motion in right ascension directionmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion in declination direction of the source (ICRS) at Ep=2016.0mas/yrpos.pm;pos.eq.decfloate_pmDEStandard error of proper motion in declination directionmas/yrstat.error;pos.pm;pos.eq.decfloatpmGLONProper motion in Galactic longitude directionmas/yrpos.pm;pos.galactic.londoublee_pmGLONError on proper motion in Galactic longitude directionmas/yrstat.errordoublepmGLATProper motion in Galactic latitude directionmas/yrpos.pm;pos.galactic.latdoublee_pmGLATError on proper motion in Galactic latitudemas/yrstat.errordoublelogTeffMedian logarithm of the SED-fitted effective temperaturelog(K)phys.temperature.effective;stat.medianfloatb_logTeff16th percentile logarithm of the SED-fitted effective temperaturelog(K)phys.temperature.effectivefloatB_logTeff84th percentile logarithm of the SED-fitted effective temperaturelog(K)phys.temperature.effectivefloatlogLumMedian logarithm of the SED-fitted luminositylog(solLum)phys.luminosityfloatb_logLum16th percentile logarithm of the SED-fitted stellar luminositylog(solLum)phys.luminosityfloatB_logLum84th percentile logarithm of the SED-fitted luminositylog(solLum)phys.luminosityfloatlogMassMedian logarithm of the SED-fitted stellar masslog(solMass)phys.massfloatb_logMass16th percentile logarithm of the SED-fitted stellar masslog(solMass)phys.massfloatB_logMass84th percentile logarithm of the SED-fitted masslog(solMass)phys.massfloatDistMedian SED-fitted distancepcpos.distancedoubleb_Dist16th percentile SED-fitted distancepcpos.distancedoubleB_Dist84th percentile SED-fitted distancepcpos.distancedoubleAVMedian extinction in the V-bandmagphys.absorptiondoubleb_AV? 16th percentile of the extinction in the V-bandmagphys.absorptiondoublenullableB_AV? 84th percentile of the extinction in the V-bandmagphys.absorptiondoublenullableCluster[0-17] Cluster assigned to each star (0 if not in any cluster)meta.id.parentintProbCluster probability membershipstat.probabilityfloat