J/A+A/631/A124ivo://CDS.VizieR/J/A+A/631/A124doi:10.26093/cds/vizier.36310124CDSAlonso-Santiago J.Negueruela I.Marco A.Tabernero H.M.,Gonzalez-Fernandez C.Castro N.2022-04-07T07:52:30Z2019-11-05T08:13:53ZCDS support team

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

cds-question@unistra.fropen-star-clustersvisible-astronomymedium-band-photometryinfrared-photometryNGC 2345 is a young open cluster hosting seven blue and red supergiants, low metallicity and a high fraction of Be stars which makes it a privileged laboratory to study stellar evolution. We aim to improve the determination of the cluster parameters and study the Be phenomenon. Our objective is also to characterise its seven evolved stars by deriving their atmospheric parameters and chemical abundances. We performed a complete analysis combining for the first time ubvy photometry with spectroscopy as well as Gaia Data Release 2. We obtained spectra with classification purposes for 76 stars and high-resolution spectroscopy for an in-depth analysis of the blue and red evolved stars. We identify a new red supergiant and 145 B-type likely members within a radius of 18.7+/-1.2arcmin, which implies an initial mass, M_cl_~5,200M_{sun}_. We find a distance of 2.5+/-0.2kpc for NGC 2345, placing it at R_GC_=10.2+/-0.2kpc. Isochrone fitting supports an age of 56+/-13Ma, implying masses around 6.5M_{sun}_ for the supergiants. A high fraction of Be stars (~10%) is found. From the spectral analysis we estimate for the cluster an average v_rad}_=+58.6+/-0.5km/1 and a low metallicity, [Fe/H]=-0.28+/-0.07. We also have determined chemical abundances for Li, O, Na, Mg, Si, Ca, Ti, Ni, Rb, Y, and Ba for the evolved stars. The chemical composition of the cluster is consistent with that of the Galactic thin disc. One of the K supergiants, S50, is a Li-rich star, presenting an A(Li)~2.1. An overabundance of Ba is found, supporting the enhanced s-process. NGC 2345 has a low metallicity for its Galactocentric distance, comparable to typical LMC stars. It is massive enough to serve as a testbed for theoretical evolutionary models for massive intermediate-mass stars.2019A&A...631A.124Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/631/A124CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/631/A124https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/631/A124http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/631/A124https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/631/A124https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/631/A124http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/631/A124GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/631/A124/tablea1 (Stroemgren photometry of NGC 2345)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/631/A124/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/631/A124/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/631/A124/tablea1?GETtext/xml+votable180.050000true106.675384521-13.3894357680.005555555555555556Cone search capability for table J/A+A/631/A124/tablea2 (For every star with spectroscopy the equatorial coordinates, spectral type, radial velocity (from the AA{OMEGA} spectrum), spectrographs used, and cluster membership are displayed.)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/631/A124/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/631/A124/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/631/A124/tablea2?GETtext/xml+votable180.050000true107.060083333-13.2686388890.0055555555555555565/5408 6/216361.398457827073138e-19 1.7798557115773645e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/631/A124?format=asciiOpticalInfrareddefaultJ/A+A/631/A124/tablea1Stroemgren photometry of NGC 2345recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMoreindicates photometric and astrometric data in tablea4, and/or informations in tablea2meta.ref.urlcharID[1/2153] ID numbermeta.id;meta.mainintprimaryRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainVmagCalibrated Johnson V-magnitude bandmagphot.mag;em.opt.Vfloate_Vmagrms uncertainty on Vmagmagstat.error;phot.magfloatb-yStroemgren (b-y) colour indexmagphot.color;em.opt.B;em.opt.Vfloate_b-yrms uncertainty on (b-y)magstat.error;phot.color;em.opt.Bfloatm1Stroemgren m1 indexmagphot.colorfloate_m1rms uncertainty on m1magstat.errorfloatc1Stroemgren c1 indexmagphot.colorfloate_c1rms uncertainty on c1magstat.errorfloatNNumber of measurements for each starmeta.numberintJ/A+A/631/A124/tablea2For every star with spectroscopy the equatorial coordinates, spectral type, radial velocity (from the AA{OMEGA} spectrum), spectrographs used, and cluster membership are displayed.SimbadNameSimbad column added by the CDSmeta.idcharnullableStarStar namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID? ID numbermeta.idintnullableRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainSpTypeSpectral typesrc.spTypecharRV? Radial velocity from the AA spectrumkm/sphys.veloc;pos.heliocentricintnullableAAO[*-] *: AA{OMEGA} spectrograph usedmeta.codecharWYFFOS[*-] *: WYFFOS spectrograph usedmeta.codecharFEROS[*-] *: FEROS spectrograph usedmeta.codecharISIS[*-] *: ISIS spectrograph usedmeta.codecharIDS[*-] *: IDS spectrograph usedmeta.codecharMemberCluster membershipmeta.code.membercharJ/A+A/631/A124/tablea3Gaia DR2 astrometric data for all stars in field of NGC 2345 for which we have spectra and other objects discussed in textrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStatusMembership status (1)meta.codecharStarStar namemeta.id;meta.maincharplxGaia-DR2 Parallaxmaspos.parallax.trigfloate_plxGaia-DR2 Parallax uncertaintymasstat.error;pos.parallaxfloatpmRA*Gaia-DR2 Proper motion along RA, pmRA*cosDEmas/yrpos.pm;pos.eq.rafloate_pmRA*Gaia-DR2 Proper motion along RA uncertaintymas/yrstat.error;pos.pm;pos.eq.rafloatpmDEGaia-DR2 Proper motion along DEmas/yrpos.pm;pos.eq.decfloate_pmDEGaia-DR2 Proper motion along DE uncertaintymas/yrstat.error;pos.pm;pos.eq.decfloatJ/A+A/631/A124/tablea4Photometric and astrometric data for likely blue membersJ-Ks? 2MASS (J-Ks) colour indexmagphot.color;em.IR.J;em.IR.KfloatnullableGmagGaia-DR2 G-magnitude bandmagphot.mag;em.optfloatBP-RPGaia-DR2 (BP-RP) colour indexmagphot.color;em.opt.B;em.opt.Rfloatb-yStroemgren (b-y) colour indexmagphot.color;em.opt.B;em.opt.VfloatJmag? 2MASS J-magnitude bandmagphot.mag;em.IR.JfloatnullableplxGaia-DR2 parallaxmaspos.parallax.trigfloatpmRA*Gaia-DR2 proper motion along RA, pmRA*cosDEmas/yrpos.pm;pos.eq.rafloatpmDEGaia-DR2 proper motion along DEmas/yrpos.pm;pos.eq.decfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDID numbermeta.id;meta.mainintE(B-V)Colour excessmagphot.color.excessfloatVmagCalibrated Johnson V-magnitude bandmagphot.mag;em.opt.Vfloat