J/MNRAS/391/1482ivo://CDS.VizieR/J/MNRAS/391/1482doi:10.26093/cds/vizier.73911482CDSPlatais I.Melo C.Fulbright J.P.Kozhurina-Platais V.Figueira P.,Barnes S.A.Mendez R.A.2024-07-07T20:17:24Z2009-05-25T05:56:16ZCDS support team

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

cds-question@unistra.fropen-star-clustersinfrared-photometryvisible-astronomybroad-band-photometryWe show that the open cluster Trumpler 20, contrary to the earlier findings, is actually an old Galactic open cluster. New CCD photometry and high-resolution spectroscopy are used to derive the main parameters of this cluster. At [Fe/H]=-0.11 for a single red giant star, the metallicity is slightly subsolar. The best fit to the colour-magnitude diagrams is achieved using a 1.3-Gyr isochrone with convective overshoot. The cluster appears to have a significant reddening at E(B-V)=0.46 (for B0 spectral type), although for red giants this high reddening yields the colour temperature exceeding the spectroscopic Teff by about 200K. Trumpler 20 is a very rich open cluster, containing at least 700 members brighter than M_V_=+4. It may extend over the field of view available in our study at 20x20arcmin^2^.2008MNRAS.391.1482Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/391/1482CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/161/118 : Photometry of open clusters (McSwain+, 2005)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/391/1482https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/391/1482http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/391/1482https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/391/1482https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/391/1482http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/391/1482GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/391/1482/tr20 (BVI photometry in Tr 20)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/391/1482/tr20?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/391/1482/tr20?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/391/1482/tr20?GETtext/xml+votable180.050000true189.67025-60.801230.0055555555555555566/43034https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/391/1482?format=asciiOpticalInfrareddefaultJ/MNRAS/391/1482/tr20BVI photometry in Tr 20recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqSequential number, Cl* Trumpler 20 PMF NNNN in Simbadmeta.recordintRAJ2000Right ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainVmagJohnson V magnitudemagphot.mag;em.opt.Vfloate_Vmagrms uncertainty on Vmagmagstat.error;phot.mag;em.opt.VfloatB-V? Johnson B-V colour indexmagphot.color;em.opt.B;em.opt.Vfloatnullablee_B-V? rms uncertainty on B-Vmagstat.error;phot.color;em.opt.Bfloatnullableo_B-VNumber of observations in B-Vmeta.numberintV-Ic? Johnson-Cousins V-Ic colour indexmagphot.color;em.opt.V;em.opt.Ifloatnullablee_V-Ic? rms uncertainty on V-Icmagstat.error;phot.color;em.opt.Vfloatnullableo_V-IcNumber of observations in V-Icmeta.numberint