J/AZh/81/1104ivo://CDS.VizieR/J/AZh/81/1104CDSKlochkova V.G.Chentsov E.L.2006-04-13T12:34:55Z2006-04-13T12:33:10ZCDS support team

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

cds-question@unistra.frvariable-starsline-intensitiesradial-velocityWe have obtained the first high spectral-resolution (R=15000 and 60000) optical spectra for the extremely luminous star No.12, identified with the IR-source IRAS 20308+4104 in the Cyg OB2 association. We have identified about 200 spectral features at 4552-7939{AA}, including interstellar NaI, KI and numerous DIBs, which are in the strongest absorptions in the spectrum, along with the HeI, CII, SiII lines. A two-dimensional spectral classification indicates that the star's spectral type is B5+/-0.5 Ia^+^. Our analyses of the radial velocities pattern shows the presence of a radial velocity gradient in the stellar atmosphere due to the infall of matter onto the star. The strong H(alpha) emission line displays broad Thompson wings and time-variable core absorption, providing evidence that the stellar wind is inhomogeneous and slightly blue-shifted P Cygni absorption profile. We conclude that the wind is time-variable.2004AZh....81.1104Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AZh/81/1104CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AZh/81/1104https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AZh/81/1104http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AZh/81/1104https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AZh/81/1104https://vizier.iucaa.in/viz-bin/votable?-source=J/AZh/81/1104http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AZh/81/1104GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/AZh/81/1104/table1Line identifications, equivalent widths, residual intensities, and heliocentric radial velocities for the spectra of Cyg OB2-No.12recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElElement (1)phys.atmol.elementcharMult? Multiplet numbermeta.id;meta.maincharLambdaWavelength expressed in Angstroem0.1nmem.wlfloatu_Lambda[:] Uncertainty flag on Lambdameta.code.errorcharEW1? Equivalent width for June 12, 20010.1nmspect.line.eqWidthfloatnullableu_EW1[:] Uncertainty flag on EW1meta.code.errorcharn_EW1[*] *: triplets combined equivalent widthmeta.notecharr1? Residual intensity for June 12, 2001spect.line.intensityfloatnullableu_r1[:] Uncertainty flag on Lambdameta.code.errorcharHRV1? Heliocentric radial velocity for June 12, 2001km/sspect.dopplerVeloc;pos.heliocentricintnullableu_HRV1[:] Uncertainty flag on HRV1meta.code.errorcharEW2? Equivalent width for April 12, 20030.1nmspect.line.eqWidthfloatnullableu_EW2[:] Uncertainty flag on EW2meta.code.errorcharr2? Residual intensity for April 12, 2003spect.line.intensityfloatnullableu_r2[:] Uncertainty flag on Lambdameta.code.errorcharHRV2? Heliocentric radial velocity for April 12, 2003km/sspect.dopplerVeloc;pos.heliocentricintnullableu_HRV2[:] Uncertainty flag on HRV2meta.code.errorchar