J/A+A/601/A133ivo://CDS.VizieR/J/A+A/601/A133doi:10.26093/cds/vizier.36010133CDSRaucq F.Gosset E.Rauw G.Manfroid J.Mahy L.Mennekens N.,Vanbeveren D.2017-06-08T12:06:49Z2017-05-23T07:08:52ZCDS support team

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

cds-question@unistra.frspectroscopic-binary-starsinfrared-photometryvisible-astronomybroad-band-photometryThe role of mass and momentum exchanges in close massive binaries is very important in the subsequent evolution of the components. Such exchanges produce several observational signatures such as asynchronous rotation and altered chemical compositions, that remain after the stars detach again. We investigated these effects for the close O-star binary LSS 3074 (O4f+O6-7:(f):), which is a good candidate for a past Roche lobe overflow (RLOF) episode because of its very short orbital period, P=2.185-days, and the luminosity classes of both components. We determined a new orbital solution for the system. We studied the photometric light curves to determine the inclination of the orbit and Roche lobe filling factors of both stars. Using phase-resolved spectroscopy, we performed the disentangling of the optical spectra of the two stars. We then analysed the reconstructed primary and secondary spectra with the CMFGEN model atmosphere code to determine stellar parameters, such as the effective temperatures and surface gravities, and to constrain the chemical composition of the components. We confirm the apparent low stellar masses and radii reported in previous studies. We also find a strong overabundance in nitrogen and a strong carbon and oxygen depletion in both primary and secondary atmospheres, together with a strong enrichment in helium of the primary star. We propose several possible evolutionary pathways through a RLOF process to explain the current parameters of the system. We confirm that the system is apparently in overcontact configuration and has lost a significant portion of its mass to its surroundings. We suggest that some of the discrepancies between the spectroscopic and photometric properties of LSS 3074 could stem from the impact of a strong radiation pressure of the primary.2017A&A...601A.133Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/601/A133CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/590/A85 : Massive LMC eclipsing binaries minima timings (Zasche+, 2016)J/ApJ/748/96 : Massive binaries in the LMC (Massey+, 2012)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/601/A133https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/601/A133http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/601/A133https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/601/A133https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/601/A133http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/601/A133GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/601/A133/stars (List of studied stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/601/A133/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/601/A133/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/601/A133/stars?GETtext/xml+votable180.050000true201.7492917-62.03036110.0055555555555555566/41697https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/601/A133?format=asciiInfraredOpticaldefaultJ/A+A/601/A133/tablea3Photometric data of LSS 3072recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBand[BVRI] Observed bandinstr.bandpasscharHJDDate of the observation (HJD-2450000)dtime.epochdoublemagMagnitude in Bandphot.magfloatJ/A+A/601/A133/starsList of studied starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainFileNameName of the file with photometrymeta.id;phot;meta.filecharLCShow the light curvesmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/601/A133/tablea1Photometric data of LSS 3074recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBand[BVRI] Observed bandinstr.bandpasscharHJDDate of the observation (HJD-2450000)dtime.epochdoublemagMagnitude in Bandphot.magfloatJ/A+A/601/A133/tablea2Photometric data of HD 116827recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBand[BVRI] Observed bandinstr.bandpasscharHJDDate of the observation (HJD-2450000)dtime.epochdoublemagMagnitude in Bandphot.magfloat