J/ApJ/660/1486ivo://CDS.VizieR/J/ApJ/660/1486doi:10.26093/cds/vizier.16601486CDSSoszynski I.2009-04-19T22:12:10Z2009-04-19T22:07:00ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsvariable-starsgiant-starsObservational arguments supporting the binary explanation of the long secondary period (LSP) phenomenon in red giants are presented. Photometry of about 1200 semiregular variables with LSPs in the Large Magellanic Cloud is analyzed using the MACHO and OGLE photometry. For about 5% of these objects, additional ellipsoidal-like or eclipsing-like modulation with the same periods as the LSP is detectable. These double-humped variations are usually shifted in phase compared to LSP light curves. I discuss the model of a binary system with a red giant as the primary component and a low-mass object as the secondary. The mass lost by the red giant through the wind follows a spiral pattern in the orbit around the primary star and obscures it, causing LSP variations.2007ApJ...660.1486Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/660/1486CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/247 : Variable Stars in the Large Magellanic Clouds (MACHO, 2001)J/AcA/54/347 : IVB mag of LMC ellipsoidal variables (Soszinski+, 2004)http://wwwmacho.mcmaster.ca/Data/MachoData.html : MACHO Home Pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/660/1486https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/660/1486http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/660/1486https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/660/1486https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/660/1486http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/660/1486GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/660/1486/stars (Additional information for the sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/660/1486/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/660/1486/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/660/1486/stars?GETtext/xml+votable180.050000true83.1264583-69.79291670.0055555555555555565/8272 8274 6/33053 33077 33120https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/660/1486?format=asciiOpticaldefaultJ/ApJ/660/1486/table1The residual data for 61 LSP stars with double-humped variationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMACHOThe MACHO identificationmeta.id;meta.maincharHJDHeliocentric Julian Datedtime.epochdoubleDmagDifferential magnitude (1)magphot.mag;arith.difffloate_DmagError in Dmagmagstat.error;phot.mag;arith.difffloatJ/ApJ/660/1486/starsAdditional information for the sourcesPerPerioddtime.periodfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMACHOMACHO identificationmeta.id;meta.maincharOGLEOGLE identification (lmc_scNN_NNNNNNN)meta.idcharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainA(B)/A(R)Amplitude ratio A(B)/A(R)src.var.amplitude;arith.ratiofloatLCPlot the light curvemeta.ref.urlchar