J/A+A/624/A126ivo://CDS.VizieR/J/A+A/624/A126doi:10.26093/cds/vizier.36240126CDSCantat-Gaudin T.Krone-Martins A.Sedaghat N.Farahi A.de Souza R.S.,Skalidis R.Malz A.I.Macedo S.Moews B.Jordi C.Moitinho A.,Castro-Ginard A.Ishida E.E.O.Heneka C.Boucaud A.Trindade A.M.M.2021-01-08T17:32:27Z2019-04-24T06:45:20ZCDS support team

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

cds-question@unistra.fropen-star-clustersOpen clusters (OCs) are popular tracers of the structure and evolutionary history of the Galactic disk. The OC population is often considered to be complete within 1.8kpc of the Sun. The recent Gaia Data Release 2 (DR2) allows the latter claim to be challenged. We perform a systematic search for new OCs in the direction of Perseus using precise and accurate astrometry from Gaia DR2. We implement a coarse-to-fine search method. First, we exploit spatial proximity using a fast density-aware partitioning of the sky via a k-d tree in the spatial domain of Galactic coordinates, (l, b). Secondly, we employ a Gaussian mixture model in the proper motion space to quickly tag fields around OC candidates. Thirdly, we apply an unsupervised membership assignment method, UPMASK, to scrutinise the candidates. We visually inspect colour-magnitude diagrams to validate the detected objects. Finally, we perform a diagnostic to quantify the significance of each identified overdensity in proper motion and in parallax space We report the discovery of 41 new stellar clusters. This represents an increment of at least 20% of the previously known OC population in this volume of the Milky Way. We also report on the clear identification of NGC 886, an object previously considered an asterism. This letter challenges the previous claim of a near-complete sample of open clusters up to 1.8 kpc. Our results reveal that this claim requires revision, and a complete census of nearby open clusters is yet to be found.2019A&A...624A.126Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/624/A126CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/624/A126https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/624/A126http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/624/A126https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/624/A126https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/624/A126http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/624/A126GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/624/A126/tablea1 (Mean parameters of the OCs characterised in this study)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/624/A126/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/624/A126/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/624/A126/tablea1?GETtext/xml+votable180.050000true11.93366.7690.005555555555555556Cone search capability for table J/A+A/624/A126/members (List of all members)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/624/A126/members?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/624/A126/members?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/624/A126/members?GETtext/xml+votable180.050000true14.8384236028767.026417996810.0055555555555555565/319-320 324 327 329 334-335 345-348 362 774 800 818-819 903 5946 5994 6083 6/1269-1271 1273 1275 1288-1289 1293-1295 1300 1302 1306 1315 1321 1324 1328-1329 1332-1333 1355 1357-1359 1368 1370-1371 1377-1379 1400 1429 1431 1442 1452 1454 1472-1473 1475-1478 1792-1793 1796 2922-2923 2926 2943 3008-3009 3012 3029 3062-3063 3090-3091 3094 3100 3102 3115 3118 3139 3142 3145 3147-3148 3150 3204 3206 3258-3259 3263 3267 3270-3271 3288 3297 3300-3301 3306 3593 3595-3598 3600-3601 3604-3606 3611 3617 3620 3625-3628 3630 3636-3638 3651 3654-3655 3657 3660-3661 3712 3718 3724 3726-3727 3737-3739 3742 3748-3749 3760-3761 3782-3783 3788-3789 3794 3800 23665 23667-23668 23670 23735 23741 23743 23778-23779 23806-23807 23980 23982 24128 24130-24131 24148-24149 24320-24321 24324 24326-24327 24338 24344 24346 24365-24367 24376 24378 24427 24430 24452-24453 24460-24461 24464 24506-24507 24510 24513 24516https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/624/A126?format=asciidefaultJ/A+A/624/A126/tablea1Mean parameters of the OCs characterised in this studyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNoteCluster category (Grade A, Grade B, known)meta.notecharClusterCluster namemeta.id.parentcharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latfloatr50Radius containing half the members identified in this studydegphys.angSize;srcfloatNNumber of stars with the most frequent membership probability >=50%meta.numberintpmRA*Proper motion along RA, pmRA*cosDEmas/yrpos.pm;pos.eq.rafloate_pmRA*rms uncertainty on pmRA*mas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion along DEmas/yrpos.pm;pos.eq.decfloate_pmDErms uncertainty on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatplxParallaxmaspos.parallax.trigfloate_plxrms uncertainty on Plxmasstat.error;pos.parallaxfloatdMode of the distance likelihood after adding +0.029mas to the measured parallaxespcpos.angDistanceintSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/624/A126/membersList of all membersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA_ICRSBarycentric right ascension (ICRS) at Ep=2015.5 (ra)degpos.eq.ra;meta.mainindexedDE_ICRSBarycentric declination (ICRS) at Ep=2015.5 (dec)degpos.eq.dec;meta.mainindexedSourceGaia DR2 Unique source identifier (source_id)meta.id;meta.mainGLONGalactic longitude (l)degpos.galactic.lonGLATGalactic latitude (b)degpos.galactic.latdoublePlxAbsolute stellar parallax (parallax)maspos.parallaxdoublee_PlxStandard error of parallax (parallax_error)masstat.error;pos.parallaxfloatpmRA*Proper motion in right ascension direction (pmRA*cosDE) (pmra)mas/yrpos.pm;pos.eq.radoublee_pmRA*Standard error of proper motion in right ascension direction (pmra_error)mas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion in declination direction (pmdec)mas/yrpos.pm;pos.eq.decdoublee_pmDEStandard error of proper motion in declination direction (pmdec_error)mas/yrstat.error;pos.pm;pos.eq.decfloatRADEcorCorrelation between right ascension and declination (ra_dec_corr)stat.correlationRAPlxcorCorrelation between right ascension and parallax (ra_parallax_corr)stat.correlationRApmRAcorCorrelation between right ascension and proper motion in right ascension (ra_pmra_corr)stat.correlationRApmDEcorCorrelation between right ascension and proper motion in declination (ra_pmdec_corr)stat.correlationDEPlxcorCorrelation between declination and parallax (dec_parallax_corr)stat.correlationDEpmRAcorCorrelation between declination and proper motion in right ascension (dec_pmra_corr)stat.correlationDEpmDEcorCorrelation between declination and proper motion in declination (dec_pmdec_corr)stat.correlationPlxpmRAcorCorrelation between parallax and proper motion in right ascension (parallax_pmra_corr)stat.correlationfloatPlxpmDEcorCorrelation between parallax and proper motion in declination (parallax_pmdec_corr)stat.correlationfloatpmRApmDEcorCorrelation between proper motion in right ascension and proper motion in declination (pmra_pmdec_corr)stat.correlationfloato_GmagNumber of observations contributing to G photometry (phot_g_n_obs)meta.numberintGmagG-band mean magnitude (Vega) (phot_g_mean_mag)magphot.mag;em.optdoubleBP-RP? BP-RP colour (photBpMeanMag-photRMeanMag) (bp_rp)magphot.color;em.opt.B;em.opt.Rdoublenullableproba[0/1] Membership probability (proba)stat.fit.goodnessdoubleClusterCluster name (cluster)meta.id.parentcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decnullableindexed