J/MNRAS/480/5242ivo://CDS.VizieR/J/MNRAS/480/5242doi:10.26093/cds/vizier.74805242CDSKos J.de Silva G.Buder S.Bland-Hawthorn J.Sharma S.Asplund M.,D'Orazi V.Duong L.Freeman K.Lewis G.F.Lin J.Lind K.,Martell S.L.Schlesinger K.J.Simpson J.D.Zucker D.B.Zwitter T.,Bedding T.R.Cotar K.Horner J.Nordlander T.Stello D.Ting Y.-S.,Traven G.2024-08-18T20:21:31Z2022-06-29T13:43:46ZCDS support team

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

cds-question@unistra.frradial-velocityproper-motionssurveysopen-star-clusterschemical-abundancesvisible-astronomySparse open clusters can be found at high galactic latitudes where loosely populated clusters are more easily detected against the lower stellar background. Because most star formation takes place in the thin disc, the observed population of clusters far from the Galactic plane is hard to explain. We combined spectral parameters from the GALAH survey with the Gaia DR2 catalogue to study the dynamics and chemistry of five old sparse high-latitude clusters in more detail. We find that four of them (NGC 1252, NGC 6994, NGC 7772, NGC 7826) - originally classified in 1888 - are not clusters but are instead chance projections on the sky. Member stars quoted in the literature for these four clusters are unrelated in our multidimensional physical parameter space; the quoted cluster properties in the literature are therefore meaningless. We confirm the existence of visually similar NGC 1901 for which we provide a probabilistic membership analysis. An overdensity in three spatial dimensions proves to be enough to reliably detect sparse clusters, but the whole six-dimensional space must be used to identify members with high confidence, as demonstrated in the case of NGC 1901.2018MNRAS.480.5242Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/480/5242CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)J/MNRAS/478/4513 : GALAH Survey DR2 (Buder+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/480/5242https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/480/5242http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/480/5242https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/480/5242https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/480/5242http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/480/5242GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/480/5242/table2 (Final parameters for NGC 1901)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/480/5242/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/480/5242/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/480/5242/table2?GETtext/xml+votable180.050000true79.49-68.3420.005555555555555556Cone search capability for table J/MNRAS/480/5242/tablea1 (*Coordinates, proper motions, parallax, and radial velocity (where known) of NGC 1252 members from the literature)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/480/5242/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/480/5242/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/480/5242/tablea1?GETtext/xml+votable180.050000true47.4215-57.63470.005555555555555556Cone search capability for table J/MNRAS/480/5242/tablea2 (*Coordinates, proper motions, parallax, and radial velocity (where known) of NGC 6994 members from the literature)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/480/5242/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/480/5242/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/480/5242/tablea2?GETtext/xml+votable180.050000true314.7366-12.64180.005555555555555556Cone search capability for table J/MNRAS/480/5242/tablea3 (*Coordinates, proper motions, parallax, and radial velocity (where known) of NGC 7772 members from the literature)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/480/5242/tablea3?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/480/5242/tablea3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/480/5242/tablea3?GETtext/xml+votable180.050000true357.991716.2920.005555555555555556Cone search capability for table J/MNRAS/480/5242/tablea4 (*Coordinates, proper motions, parallax, and radial velocity (where known) of NGC 7826 members from the literature)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/480/5242/tablea4?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/480/5242/tablea4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/480/5242/tablea4?GETtext/xml+votable180.050000true1.3897-20.85880.005555555555555556Cone search capability for table J/MNRAS/480/5242/tableb1 (List of most probable NGC 1901 members ordered by probability)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/480/5242/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/480/5242/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/480/5242/tableb1?GETtext/xml+votable180.050000true79.5799-68.44030.0055555555555555566/16631 16637 16802 16808 19693 19695 19704 33098-33100 33102-33103 33567 33588-33589 33591 489471.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/480/5242?format=asciiOpticaldefaultJ/MNRAS/480/5242/table2Final parameters for NGC 1901SimbadNameSimbad column added by the CDSmeta.idcharnullable_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.recordintRA_ICRSRight Ascension (ICRS) at Ep=2015.5 from GAIA DR2 (1)degpos.eq.ra;meta.maine_RA_ICRSError on RAdeg (1)degstat.error;pos.eq.rafloatDE_ICRSDeclination (ICRS) at Ep=2015.5 from GAIA DR2 (1)degpos.eq.dec;meta.maine_DE_ICRSError on DEdeg (1)degstat.error;pos.eq.decfloatGLONGalactic longitude (1)degpos.galactic.lone_GLONError on GLON (1)degstat.errorfloatl_rtLower limit of rt (3)meta.code.errorcharGLATGalactic latitude (1)degpos.galactic.latfloate_GLATError on GLAT (1)degstat.errorfloatr0Core radius, where the radial density profile falls sharply (2)arcsecphys.angSizefloate_r0Error on r0 (2)arcsecstat.errorfloatr1Radius at which the density stops abruptly (2)arcsecphys.angSize;srcfloate_r1Error on r1 (2)arcsecstat.errorfloatr2Radius at which the density becomes indistinguishable from the density of the surrounding field (2)arcsecphys.angSize;srcfloate_r2Error on r2 (2)arcsecstat.errorfloatrcFitted King's core radius (3)arcsecphys.angSize;srcfloate_rcError on rc (3)arcsecstat.errorfloatrtFitted King's tidal radius (3)arcsecphys.angSize;srcintpmRAProper motion in right ascension (pmRAxcosDE) (4)mas/yrpos.pm;pos.eq.rafloate_pmRAError on pmRA (4)mas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion in declination (4)mas/yrpos.pm;pos.eq.decfloate_pmDEError on pmDE (4)mas/yrstat.error;pos.pm;pos.eq.decfloatRVRadial velocity (5)km/sphys.veloc;pos.heliocentricfloate_RVError on RV (5)km/sstat.errorfloatplxParallaxmaspos.parallax.trigfloate_plxError on plxmasstat.error;pos.parallaxfloatDistDistance inferred from plx (6)pcpos.distancefloate_DistError on Dist (6)pcstat.errorfloatsigRVVelocity dispersion (5)km/sphys.veloc.dispersionfloate_sigRVError on sigRV (5)km/sstat.errorfloat[Fe/H]Iron abundance (7)phys.abund.Fefloate_[Fe/H]Error on [Fe/H] (7)stat.error;phys.abund.Fefloat[alpha/Fe]{alpha}-element to iron abundance ratio (7)phys.abundfloate_[alpha/Fe]Error on [alpha/Fe] (7)stat.error;phys.abundfloatlogAgeAge calculated by isochrone fittinglog(yr)time.age;meta.modelledfloate_logAgeError on logAgelog(yr)stat.error;time.agefloatJ/MNRAS/480/5242/tablea1*Coordinates, proper motions, parallax, and radial velocity (where known) of NGC 1252 members from the literatureSimbadNameSimbad column added by the CDSmeta.idcharnullable_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.decindexedpmRAProper motion in right ascension (pmRAxcosDE)mas/yrpos.pm;pos.eq.rafloate_pmRAError on pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion on declinationmas/yrpos.pm;pos.eq.decfloate_pmDEError on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatplxParallaxmaspos.parallax.trigfloate_plxError on plxmasstat.error;pos.parallaxfloatRV? Radial velocitykm/sphys.veloc;pos.heliocentricfloatnullablee_RV? Error on RVkm/sstat.errorfloatnullabler_RV? Reference of the values of RV (1)meta.ref;pos.framecharMembRefMember reference (2)meta.bibcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA_ICRSRight ascension (ICRS) at Ep=2015.5 from GAIA DR2degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2015.5 from GAIA DR2degpos.eq.dec;meta.mainJ/MNRAS/480/5242/tablea2*Coordinates, proper motions, parallax, and radial velocity (where known) of NGC 6994 members from the literatureSimbadNameSimbad column added by the CDSmeta.idcharnullable_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.recordintRA_ICRSRight ascension (ICRS) at Ep=2015.5 from GAIA DR2degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2015.5 from GAIA DR2degpos.eq.dec;meta.mainpmRAProper motion in right ascension (pmRAxcosDE)mas/yrpos.pm;pos.eq.rafloate_pmRAError on pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion on declinationmas/yrpos.pm;pos.eq.decfloate_pmDEError on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatplxParallaxmaspos.parallax.trigfloate_plxError on plxmasstat.error;pos.parallaxfloatRV? Radial velocitykm/sphys.veloc;pos.heliocentricfloatnullablee_RV? Error on RVkm/sstat.errorfloatnullabler_RV? Reference of the values of RV (1)meta.ref;pos.framecharMembRefMember reference (2)meta.bibcharJ/MNRAS/480/5242/tablea3*Coordinates, proper motions, parallax, and radial velocity (where known) of NGC 7772 members from the literatureSimbadNameSimbad column added by the CDSmeta.idcharnullable_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.decindexede_plxError on plxmasstat.error;pos.parallaxfloatRV? Radial velocitykm/sphys.veloc;pos.heliocentricfloatnullablee_RV? Error on RVkm/sstat.errorfloatnullabler_RV? Reference of the values of RV (1)meta.ref;pos.framecharMembRefMember reference (2)meta.bibcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRA_ICRSRight ascension (ICRS) at Ep=2015.5 from GAIA DR2degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2015.5 from GAIA DR2degpos.eq.dec;meta.mainpmRAProper motion in right ascension (pmRAxcosDE)mas/yrpos.pm;pos.eq.rafloate_pmRAError on pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion on declinationmas/yrpos.pm;pos.eq.decfloate_pmDEError on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatplxParallaxmaspos.parallax.trigfloatJ/MNRAS/480/5242/tablea4*Coordinates, proper motions, parallax, and radial velocity (where known) of NGC 7826 members from the literatureSimbadNameSimbad column added by the CDSmeta.idcharnullable_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.recordintRA_ICRSRight ascension (ICRS) at Ep=2015.5 from GAIA DR2degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2015.5 from GAIA DR2degpos.eq.dec;meta.mainpmRAProper motion in right ascension (pmRAxcosDE)mas/yrpos.pm;pos.eq.rafloate_pmRAError on pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion on declinationmas/yrpos.pm;pos.eq.decfloate_pmDEError on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatplxParallaxmaspos.parallax.trigfloate_plxError on plxmasstat.error;pos.parallaxfloatRV? Radial velocitykm/sphys.veloc;pos.heliocentricfloatnullablee_RV? Error on RVkm/sstat.errorfloatnullabler_RV? Reference of the values of RV (1)meta.ref;pos.framecharMembRefMember reference (2)meta.bibcharJ/MNRAS/480/5242/tableb1List of most probable NGC 1901 members ordered by probability_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.decindexedSimbadSimbad column added by the CDSmeta.ref.urlcharGmagGaia G-band magnitudemagphot.mag;em.optfloatRV? Radial velocitykm/sphys.veloc;pos.heliocentricfloatnullablee_RV? Error on RVkm/sstat.errorfloatnullabler_RV[*] Reference of RV (1)meta.ref;pos.framecharP5DProbability of being a member without taking into account the radial velocity of the starstat.fit.goodnessfloatP6D? Probability of being a member with radial velocity taken into accountstat.fit.goodnessfloatnullableBinary? Possible binary marked as 'y' (2)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintAbundindicates effective temperature, gravity, and abundances in tablec1meta.ref.urlcharGaiaDR2Gaia DR2 source IDmeta.id;meta.mainprimaryRA_ICRSRight ascension (ICRS) at Ep=2015.5 from GAIA DR2degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2015.5 from GAIA DR2degpos.eq.dec;meta.mainrDistance from the cluster centerdegpos.angDistancefloatpmRAProper motion in right ascension (pmRAxcosDE)mas/yrpos.pm;pos.eq.rafloate_pmRAError on pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDEProper motion on declinationmas/yrpos.pm;pos.eq.decfloate_pmDEError on pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatplxParallaxmaspos.parallax.trigfloate_plxError on plxmasstat.error;pos.parallaxfloatJ/MNRAS/480/5242/tablec1Effective temperature, gravity, and abundances for 19 elements in eight NGC 1901 starsSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR2Gaia DR2 source IDmeta.id;meta.mainTeffEffective temperatureKphys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloat[Li/Fe]? Lithium to iron abundance ratiophys.abundfloatnullable[C/Fe]? Carbon to iron abundance ratiophys.abundfloatnullable[O/Fe]Oxygen to iron abundance ratiophys.abundfloat[Na/Fe]Sodium to iron abundance ratiophys.abundfloat[Mg/Fe]Magnesium to iron abundance ratiophys.abundfloat[Al/Fe]? Aluminum to iron abundance ratiophys.abundfloatnullable[Si/Fe]? Silicon to iron abundance ratiophys.abundfloatnullable[K/Fe]Potassium to iron abundance ratiophys.abundfloat[Ca/Fe]? Calcium to iron abundance ratiophys.abundfloatnullable[Sc/Fe]? Scandium to iron abundance ratiophys.abundfloatnullable[Ti/Fe]? Titanium to iron abundance ratiophys.abundfloatnullable[Cr/Fe]? Chromium to iron abundance ratiophys.abundfloatnullable[Mn/Fe]? Manganese to iron abundance ratiophys.abundfloatnullable[Fe/H]Iron abundancephys.abund.Fefloat[Ni/Fe]? Nickel to iron abundance ratiophys.abundfloatnullable[Cu/Fe]? Copper to iron abundance ratiophys.abundfloatnullable[Zn/Fe]? Zinc to iron abundance ratiophys.abundfloatnullable[Y/Fe]? Yttrium to iron abundance ratiophys.abundfloatnullable[Ba/Fe]Barium to iron abundance ratiophys.abundfloat