J/A+A/543/A39ivo://CDS.VizieR/J/A+A/543/A39doi:10.26093/cds/vizier.35430039CDSFranco G.A.P.2017-10-12T13:00:29Z2012-06-25T07:42:27ZCDS support team

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

cds-question@unistra.frvisible-astronomymedium-band-photometryWe investigate the distribution of the interstellar dust towards six small volumes of the sky in the region of the Gum nebula. New high-quality four-colour uvby and H-beta Stromgren photometry obtained for 352 stars in six selected areas of Kapteyn, complemented with data obtained in a previous investigation for two of these areas, were used to estimate the colour excess and distance to these objects. The obtained colour excess versus distance diagrams, complemented with other information, when available, were analysed in order to infer the properties of the interstellar medium permeating the observed volumes. On the basis of the overall standard deviation in the photometric measurements, we estimate that colour excesses and distances are determined with an accuracy of 0.010mag and better than 30%, respectively, for a sample of 520 stars. A comparison with 37 stars in common with the new Hipparcos catalogue attests to the high quality of the photometric distance determination. The obtained colour excess versus distance diagrams testify to the low density volume towards the observed lines-of-sight. Very few stars out to distances of 1kpc from the Sun have colour excesses larger than E(b-y)=0.1mag. In spite of the low density character of the interstellar medium towards the Puppis-Vela direction, the obtained reddening as a function of the distance indicates that two or more interstellar structures are crossed towards the observed lines-of-sight. One of these structures may be associated with the very low density wall of the Local Cavity, which has a distance of 100-150pc from the Sun. Another structure might be related to the Gum nebula, and if so, its front face would be located at about 350pc from the Sun.2012A&A...543A..39Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/543/A39CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/352/600 : O+B stars uvby-Hbeta photometry. I. (Kaltcheva+, 1999)J/A+A/432/491 : CCD UBVIc photometry of Pismis 8 and Pismis 13 (Giorgi+, 2005)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/543/A39https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/543/A39http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/543/A39https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/543/A39https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/543/A39http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/543/A39GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/543/A39/table1 (uvby-beta photometry for 352 stars earlier than G0 in six selected areas of Kapteyn)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/543/A39/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/543/A39/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/543/A39/table1?GETtext/xml+votable180.050000true104.3875-30.350280.0055555555555555564/2485 5/9611 9614 9863 9868 9955 9958 9961 9964 10008-10010 6/38439 38448 38450-38451 38461 38529 38532 38535 39134-39135 39156 39159 39298 39306 39308 39310 39329 39419 39476-39477 39479 39481 39483-39486 39490 39496 39498 39520 39522 39569 39749 39751 39757 39759 39792-39793 39796 39815 39819 39826 39838 39841 39843 39853 39864 39989 39991 39996-39997 39999 40011 40014 40044-40046 40056 40128 404503.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/543/A39?format=asciiOpticaldefaultJ/A+A/543/A39/table1uvby-beta photometry for 352 stars earlier than G0 in six selected areas of KapteynrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarIdentification in the Potsdam Catalog (1)meta.id;meta.maindoubleHD? Identification in the HD Catalogmeta.idintnullableSpTypeMichigan Classification (2)src.spTypecharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainVmagV magnitudemagphot.mag;em.opt.Vfloate_VmagUncertainty in Vmagmmagstat.error;phot.mag;em.opt.Vintb-yStromgren b-y colour indexmagphot.color;em.opt.B;em.opt.Vfloate_b-yUncertainty in b-ymmagstat.error;phot.color;em.opt.Bintm1Stromgren m1 colour indexmagphot.colorfloate_m1Uncertainty in m1mmagstat.errorintc1Stromgren c1 colour indexmagphot.colorfloate_c1Uncertainty in c1mmagstat.errorintNnNumber of nights in which the star observed in uvbymeta.numberintHbHbeta indexmagspect.index;em.line.Hbetafloate_HbUncertainty in Hbetammagstat.errorinto_HbNumber of nights in which the star observed in Hbetameta.numberintSimbadSimbad column added by the CDSmeta.refchar