J/A+A/372/95ivo://CDS.VizieR/J/A+A/372/95doi:10.26093/cds/vizier.33720095CDSKaltcheva N.T.Gredel R.Fabricius C.2012-11-13T12:39:49Z2001-06-09T17:49:36ZCDS support team

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

cds-question@unistra.frvisible-astronomymedium-band-photometryearly-type-starsThe structure of the field surrounding the Galactic cluster NGC 2439 is studied utilizing uvby{beta} photometry of bright OB stars. We collate all photometric and kinematic data available to identify possible groupings. The stars of our sample show a large scatter in their distances, radial velocities, proper motions and reddenings. We conclude that they do not belong to a single stellar association. We find evidence of the existence of three coherent structures at distances of 370pc, 1kpc, and 2.6-3.2kpc. The high stellar density toward NGC 2439 is very likely due to a decreased absorption in this direction, which poses some doubt on the reality of the cluster. A comprehensive uvby{beta} study of NGC 2439 is required to clarify its nature. The spatial distribution of the stars and their reddening are used to characterise the spatial distribution of the visual extinction in the region. The results obtained confirm previously determined constraints on the formation mechanism of interstellar CH^+^ towards the NGC 2439 field.2001A&A...372...95Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/372/95CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/135 : Henry Draper Catalogue and Extension (Cannon+ 1918-1924; ADC 1989)I/108 : Cape Photographic Durchmusterung (Gill+ 1895-1900)III/43 : Luminous Stars in the Southern Milky Way (Stephenson+ 1971)I/193 : Positions and Proper Motions - South (Bastian+ 1993)II/215 : uvby-beta Catalogue (Hauck+ 1997)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/372/95https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/372/95http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/372/95https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/372/95https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/372/95http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/372/95GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/372/95/table2 (NGC 2439 photometric data and derived quantities)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/372/95/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/372/95/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/372/95/table2?GETtext/xml+votable180.050000true113.0888-28.13880.0055555555555555566/39402 39407 39699-39700 39703-39704 39711 39729-39730 39732-39733 39739-39742 39744 39748 39752 39754 39757 39761-39762 39771 39776 39778 39780 39782-39783 39793 39800 39802-39803 39806 39827-39828 39873 39876-398783.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/372/95?format=asciiOpticaldefaultJ/A+A/372/95/table2NGC 2439 photometric data and derived quantitiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHD? HD (Cat. <III/135>) numbermeta.idintnullableCPD? CPD (Cat. <I/108>)numbermeta.idintnullableLS? LS (Cat. <III/43>)numbermeta.idintnullablePPM? PPM (Cat. <I/193>)numbermeta.idintnullableGroup? Possible membership to a group (1)meta.code.membercharGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latSpTypeMK classificationmeta.code.class;src.classcharVmag? standard Johnson V magnitudemagphot.mag;em.opt.Vfloatnullableb-y? Stroemgren b-y indexmagphot.color;em.opt.B;em.opt.Vfloatnullablem1? Stroemgren m1 indexmagphot.colorfloatnullablec1? Stroemgren c1 indexmagphot.colorfloatnullablebeta? H{beta} indexmagphot.colorfloatnullableSource? Source of the photometric data (2)meta.ref;pos.framechar(b-y)0? Stroemgren b-y index corrected for reddeningmagphot.color;em.opt.B;em.opt.Vfloatnullablem0? Stroemgren m1 index corrected for reddeningmagphot.color.reddFreefloatnullablec0? Stroemgren c1 index corrected for reddeningmagphot.color.reddFreefloatnullableE(b-y)? Colour excess E(b-y)magphot.color.excessfloatnullableVmag0? Standard Johnson V magnitude corrected for reddeningmagphot.mag;em.opt.Vfloatnullablebeta(c0)? H{beta} index calculated from c0magspect.index;em.line.Hbeta;meta.modelledfloatnullableVMAG? Absolute V magnitudemagphys.magAbs;em.opt.Vfloatnullableu_VMAGUncertainty flag on VMAGmeta.code.errorcharr? Distancepcpos.distanceintnullableu_rUncertainty flag on rmeta.code.errorcharRV? Radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloatnullableRV2? Second radial velocity value (when variable)km/sspect.dopplerVeloc;pos.heliocentricintnullableRV3? Third radial velocity value (when variable)km/sspect.dopplerVeloc;pos.heliocentricintnullable_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexed