J/A+A/324/1059ivo://CDS.VizieR/J/A+A/324/1059doi:10.26093/cds/vizier.33241059CDSLe Bertre T.1997-12-09T16:59:30Z1997-12-09T17:59:25ZCDS support team

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

cds-question@unistra.frcarbon-starsinfrared-photometryvisible-astronomybroad-band-photometryA study of circumstellar dust shells (CDS) around carbon stars is presented. This study is based on the analysis of the 1-100{mu}m broad-band spectra of 23 objects which have been monitored in the 1-20{mu}m region over several years at ESO. The sources in the sample range from Irr/SR variables and optical Miras to Extreme Carbon Stars which have only been discovered recently in infrared surveys. A modelling accounting for the photometric variations with phase (with up to 9 spectra per object) has been developed. All the CDSs in the sample can be modelled successfully in spherical geometry with a dust opacity law {prop.to}{lambda}^-1.3^ and a dust formation temperature ~950K. The modelling favors the case of an acceleration of dust, from the site of formation and on a distance of ~10^15^cm, over the case of a uniform expansion. Mass loss rates in the range 0.1-50x10^-6^M_{sun}_/yr are derived. The estimates based on this modelling are consistent with those derived from the CO emission line measurements. In view of the incoming near-infrared surveys (DENIS and 2MASS), an analysis of the location of carbon-rich sources in color diagrams is presented. It is shown that the near-infrared colors are well correlated with the mass loss rate. This property can be used to get an estimate, within a factor 3, of this rate for carbon stars without a priori on the distance.1997A&A...324.1059Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/324/1059CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/324/1059https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/324/1059http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/324/1059https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/324/1059https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/324/1059http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/324/1059GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/A+A/324/1059/table210-20 microns photometric dataNmag? N (10.36 microns) magnitudemagphot.mag;em.IR.8-15umfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharJDJulian datedtime.epochintN1magN1 (8.38 microns) magnitudemagphot.mag;em.IR.8-15umfloatN2magN2 (9.69 microns) magnitudemagphot.mag;em.IR.8-15umfloatN3magN3 (12.89 microns) magnitudemagphot.mag;em.IR.8-15umfloatu_N3mag[)] Uncertainty flag on N3magmeta.code.errorcharQ0mag? Q0 (18.06 microns) magnitudemagphot.mag;em.IR.15-30umfloatJ/A+A/324/1059/table3UBVRI photometric dataNameStar namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian datedtime.epochintUmag? U magnitudemagphot.mag;em.opt.UfloatBmag? B magnitudemagphot.mag;em.opt.BfloatVmag? V magnitudemagphot.mag;em.opt.VfloatRmag? R magnitudemagphot.mag;em.opt.RfloatImag? I magnitudemagphot.mag;em.opt.IfloatJ/A+A/324/1059/table4Model parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameUsual namemeta.id;meta.maincharJDJulian Datedtime.epochintPhase? [0-1[ Phasetime.phasefloatTau1umOptical depth at 1 micronphys.absorption.opticalDepthfloatRcInner radius of the dust shellmpcphys.size.radiusfloatL*Bolometric luminosity100solLumphys.luminosityfloatTcGrain temperature at the inner radiusKphys.temperatureintTau1um*RcProduct of the optical depth with the inner radiusmpcphys.size.radiusfloat