J/A+A/449/305ivo://CDS.VizieR/J/A+A/449/305doi:10.26093/cds/vizier.34490305CDSAerts C.De Cat P.De Ridder J.Van Winckel H.Raskin G.,Davignon G.Uytterhoeven K.2017-07-04T07:08:34Z2006-06-08T22:02:59ZCDS support team

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

cds-question@unistra.frearly-type-starsvariable-starsvisible-astronomynarrow-band-photometryWe made a seismic study of the young massive beta Cephei star HD 203664 with the goal of constraining its interior structure. Our study is based on a time series of 328 new Geneva 7-colour photometric data of the star spread over 496.8 days. The data confirm the frequency of the dominant mode of the star, which we refined to f_1_=6.02885c/d. The mode has a large amplitude of 37mmag in V and is unambiguously identified as a dipole mode (l=2) from its amplitude ratios and non-adiabatic computations. Besides f_1_, we discovered two additional new frequencies in the star with amplitudes above 4{sigma}: f_2_=6.82902c/d and f_3_=4.81543c/d, or one of their daily aliases. The amplitudes of these two modes are only between 3 and 4mmag, which explains why they were not detected before. Their amplitude ratios are too uncertain for mode identification. We show that the observed oscillation spectrum of HD 203664 is compatible with standard stellar models but that we have insufficient information for asteroseismic inferences. Among the large-amplitude beta Cephei stars, HD 203664 stands out as the only one rotating at a significant fraction of its critical rotation velocity (~40%).2006A&A...449..305Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/449/305CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/449/305https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/449/305http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/449/305https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/449/305https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/449/305http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/449/305GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/449/305/table1Time seriesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJDHeliocentric Julian Date of mid exposuredtime.epochdoubleUmagGeneva U magnitudemagphot.mag;em.opt.UfloatB1magGeneva B1 magnitudemagphot.mag;em.UV.100-200nmfloatBmagGeneva B magnitudemagphot.mag;em.opt.BfloatB2magGeneva B2 magnitudemagphot.mag;em.opt.VfloatV1magGeneva V1 magnitudemagphot.mag;em.opt.VfloatVmagGeneva V magnitudemagphot.mag;em.opt.VfloatGmagGeneva G magnitudemagphot.mag;em.opt.Vfloat