J/AJ/148/51ivo://CDS.VizieR/J/AJ/148/51doi:10.26093/cds/vizier.51480051CDSAnthony-Twarog B.J.Deliyannis C.P.Twarog B.A.2017-10-16T14:57:21Z2014-11-27T09:02:56ZCDS support team

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

cds-question@unistra.fropen-star-clustersvisible-astronomymedium-band-photometryNGC 6819 is a richly populated, older open cluster situated within the Kepler field. A CCD survey of the cluster on the uvbyCaH{beta} system, coupled with proper-motion membership, has been used to isolate 382 highly probable, single-star unevolved main-sequence members over a 20' field centered on the cluster. From 278 F dwarfs with high precision photometry in all indices, a mean reddening of E(b-y)=0.117+/-0.005 or E(B-V)=0.160+/-0.007 is derived, where the standard errors of the mean include both internal errors and the photometric zero-point uncertainty. With the reddening fixed, the metallicity derived from the same 278 stars is [Fe/H]=-0.116+/-0.101 from m_1_ and -0.055+/-0.033 from hk, for a weighted average of [Fe/H]=-0.06+/-0.04, where the quoted standard errors of the mean include the internal errors from the photometric scatter plus the uncertainty in the photometric zero points. If metallicity is derived using individual reddening values for each star to account for potential reddening variation across the face of the cluster, the analogous result is unchanged. The cluster members at the turnoff of the color-magnitude diagram are used to test and confirm the recently discovered variation in reddening across the face of the cluster, with a probable range in the variation of {Delta}E(B-V)=0.045+/-0.015. With the slightly higher reddening and lower [Fe/H] compared to commonly adopted values, isochrone fitting leads to an age of 2.3+/-0.2Gyr for an apparent modulus of (m-M)=12.40+/-0.12.2014AJ....148...51Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/148/51CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/215 : uvby-beta Catalogue (Hauck+ 1997)J/AJ/148/38 : WIYN open cluster study. LX. RV survey of NGC 6819J/AJ/146/58 : Eclipse timings for NGC 6819-259 (Jeffries+, 2013)J/AJ/146/43 : WIYN open cluster study. LV. NGC 6819 (Platais+, 2013)J/AJ/138/159 : NGC 6819 stellar radial-velocity and photometry (Hole+, 2009)J/AJ/133/1585 : Stromgren photometry in NGC 6791 (Anthony-Twarog+, 2007)J/AJ/129/872 : Stromgren photometry of NGC 2243 (Anthony-Twarog+, 2005)J/AJ/127/1000 : Stromgren and Ca photometry of NGC 3680 (Anthony-Twarog+, 2004)J/AJ/125/1383 : Stromgren photometry of NGC 6253 (Anthony-Twarog+, 2003)J/AJ/121/327 : Metal Abundances of Red Clump Stars in NGC 6819J/AJ/119/2282 : Stromgren photometry of IC 4651 (Anthony-Twarog+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/148/51https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/148/51http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/148/51https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/148/51https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/148/51http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/148/51GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/148/51/table2 (uvbyCaH{beta} photometry of stars in the field of NGC 6819)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/148/51/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/148/51/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/148/51/table2?GETtext/xml+votable180.050000true295.1853940.305860.0055555555555555565/3688https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/148/51?format=asciiOpticaldefaultJ/AJ/148/51/table2uvbyCaH{beta} photometry of stars in the field of NGC 6819m1? Stromgren m_1_ indexmagspect.indexfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainMb[0/99]? Probability of membership (1)%stat.probabilityintnullableVmag[9.532/20.215]? Stromgren V band magnitudemagphot.mag;em.opt.Vfloatnullablee_Vmag? Uncertainty in Vmagmagstat.error;phot.mag;em.opt.Vfloatnullableb-y? Stromgren (b-y) color indexmagphot.color;em.opt.B;em.opt.Vfloatnullablee_b-y? Uncertainty in b-ymagstat.error;phot.color;em.opt.Bfloatnullablee_m1? Uncertainty in m1magstat.error;spect.indexfloatnullablec1? Stromgren c_1_ indexmagspect.indexfloatnullablee_c1? Uncertainty in c1magstat.error;spect.indexfloatnullablehk? hk indexmagspect.indexfloatnullablee_hk? Uncertainty in hkmagstat.error;spect.indexfloatnullableHb? H{beta} indexmagspect.index;em.line.Hbetafloatnullablee_Hb? Uncertainty in Hbmagstat.error;spect.indexfloatnullableNy[2/25] Number of y filter observationsmeta.number;em.optintNb[2/25] Number of b filter observationsmeta.number;em.optintNv[0/22] Number of v filter observationsmeta.number;em.optintNu[0/14] Number of u filter observationsmeta.number;em.optintNCa[0/30] Number of Ca filter observationsmeta.number;em.optintNn[0/25] Number of H{beta} narrow filter observationsmeta.number;em.optintNw[0/24] Number of H{beta} wide filter observationsmeta.number;em.optintLVSimbad column added by the CDSmeta.ref.urlintnullable