J/MNRAS/495/1888ivo://CDS.VizieR/J/MNRAS/495/1888doi:10.26093/cds/vizier.74951888CDSMurphy S.J.Paunzen E.Bedding T.R.Walczak P.Huber D.2024-08-21T20:14:32Z2023-09-05T14:58:14ZCDS support team

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

cds-question@unistra.frasteroseismologyvariable-starsmultiple-starseffective-temperaturemetallicitystellar-massesvisible-astronomytrigonometric-parallaxstellar-radiistellar-agesWe analyse TESS light curves for 70 southern {lambda} Boo stars to identify binaries and to determine which of them pulsate as {delta} Scuti stars. We find two heartbeat stars and two eclipsing binaries among the sample. We calculate that 81 per cent of {lambda} Boo stars pulsate as {delta} Sct variables, which is about twice that of normal stars over the same parameter space. We determine the temperatures and luminosities of the {lambda} Boo stars from photometry and Gaia DR2 parallaxes. A subset of 40 {lambda} Boo stars have 2-min TESS data, reliable temperatures and luminosities, and {delta} Sct pulsation. We use Petersen diagrams (period ratios), echelle diagrams, and the period-luminosity relation to identify the fundamental mode in 20 of those 40 stars and conclude that a further 8 stars are not pulsating in this mode. For the remaining 12, the fundamental mode cannot be unambiguously identified. Further mode identification is possible for 12 of the fundamental mode pulsators that have regular sequences of pulsation overtones in their echelle diagrams. We use stellar evolution models to determine statistically that the {lambda} Boo stars are only superficially metal weak. Simple pulsation models also better fit the observations at a metallicity of Z=0.01 than at Z=0.001. The TESS observations reveal the great potential of asteroseismology on {lambda} Boo stars, for determining precise stellar ages and shedding light on the origin(s) of the {lambda}Boo phenomenon.2020MNRAS.495.1888Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/495/1888CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)IV/39 : TESS Input Catalog version 8.2 (TIC v8.2) (Paegert+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/495/1888https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/495/1888http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/495/1888https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/495/1888https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/495/1888http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/495/1888GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/495/1888/table2 (Stellar parameters for the southern {lambda} Boo stars used in this paper)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/495/1888/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/495/1888/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/495/1888/table2?GETtext/xml+votable180.050000true1.945415-22.50855690.0055555555555555566/16543 16629 16703 20575 20746 21313 21388 21439 22543 22735 22850 22861 22885 23040 23408 24839 26929 28762 32863 33117 33421 33469 34680 35104 35132 35823 35986 37186 37469 37916 38109 38164 38238 38283 38420 39228 39263 39424 39596 39610 40029 40446 40869 40904 40917 41287 41555 41561 41613 42048 42093 42375 42421 42644 43306 43508 43629 43732 43851 45643 45835 45948 46211 46234 46979 47110 47520 47623 47760https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/495/1888?format=asciiOpticaldefaultJ/MNRAS/495/1888/table2Stellar parameters for the southern {lambda} Boo stars used in this paperSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMoreLink to Tables 1,3,4,5 and A1meta.ref.urlcharNameStar name (HD NNNNNN except for BD-11 1239 and T Ori)meta.id;meta.maincharprimaryVmagV-band magnitudemagphot.mag;em.opt.VfloatTeffEffective temperatureKphys.temperature.effectiveinte_TeffError on TeffKstat.error;phys.temperature.effectiveintLum? LuminositysolLumphys.luminosityfloatnullableE_Lum? Upper error on LumsolLumstat.error;stat.maxfloatnullablee_Lum? Lower error on LumsolLumstat.errorfloatnullableVMAG? Absolute V-band magnitudemagphot.magfloatnullableE_VMAG? Upper error on VMAGmagstat.error;stat.maxfloatnullablee_VMAG? Lower error on VMAGmagstat.errorfloatnullablelogg? Surface gravitylog(cm.s**-2)phys.gravityfloatnullableE_logg? Upper error on logglog(cm.s**-2)stat.error;stat.maxfloatnullablee_logg? Lower error on logglog(cm.s**-2)stat.errorfloatnullable[Fe/H]? Fe/H abundance ratiophys.abund.Fe;arith.ratiofloatnullableE_[Fe/H]? Upper error on [Fe/H]stat.error;stat.maxfloatnullablee_[Fe/H]? Lower error on [Fe/H]stat.error;phys.abund.FefloatnullableMass? Star masssolMassphys.massfloatnullableE_Mass? Upper error on MasssolMassstat.error;stat.maxfloatnullablee_Mass? Lower error on MasssolMassstat.error;phys.massfloatnullableAV? Extinction on the V-bandmagphys.absorptionfloatnullableRUWERenormalized Unit Weight Errorstat.errorfloatgood[0/1] Boolean flag indicating whether the parameters are 'good' (=1) or not (=0)meta.code.qualintDm? Magnitude difference from any companion in the WDS cataloguemagmeta.idfloatnullableSep? Separation from any companion in the WDS cataloguearcsecpos.angDistancefloatnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/MNRAS/495/1888/table1Pulsation properties, including frequencies and amplitudes, of the 70 {lambda} Boo stars in this studyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar name (HD NNNNNN except for BD-11 1239 and T Ori)meta.id;meta.maincharf1? Frequency of the first stronger peak above 4d^-1^d**-1em.freq;src.varfloatnullablea1? Amplitude associated to f1mmagmeta.id.assoc;phot.magfloatnullablef2? Frequency of the second stronger peak above 4d^-1^d**-1em.freq;src.varfloatnullablea2? Amplitude associated to f2mmagmeta.id.assoc;phot.magfloatnullablef3? Frequency of the third stronger peak above 4d^-1^d**-1em.freq;src.varfloatnullablea3? Amplitude associated to f3mmagmeta.id.assoc;phot.magfloatnullableFFIonlyFlag indicating the 14 stars with only 30-min FFI datameta.codecharlimit? Upper limit on any undetected pulsation mode for the 16 {lambda}Boo stars that are not {delta}Sct pulsatorsmmagsrc.var.amplitudefloatnullableSectorTESS sector in which each the target was observedobs.fieldcharJ/MNRAS/495/1888/table3Most likely identification of the fundamental mode for the 40 pulsating {lambda} Boo starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar name (HD NNNNNN)meta.id;meta.maincharFund? Most likely identification of the fundamental moded**-1em.freq;src.varfloatnullablef_FundFlag on Fund (1)meta.codecharMethodMethod(s) used in the identificationmeta.notecharJ/MNRAS/495/1888/table4Parameters of the eight stars chosen for pulsational analysisNameStar name (HD NNNNNN)meta.id;meta.maincharVmagV-band magnitudemagphot.mag;em.opt.VfloatvsiniProjected surface rotation velocitykm/sphys.veloc.rotatintplxGaia DR2 parallaxmaspos.parallax.trigfloate_plxError on plxmasstat.error;pos.parallaxfloatlogTeffLogarithm of the effective temperaturelog(K)phys.temperature.effectivefloate_logTeffError on logTefflog(K)stat.error;phys.temperature.effectivefloatlogLLogarithm of the star luminositylog(solLum)phys.luminosityfloate_logLError on logLlog(solLum)stat.errorfloatRadStellar radiussolRadphys.size.radiusfloate_RadError on RadsolRadstat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefLiterature references to spectroscopic abundance analysesmeta.ref;pos.parallax.spectcharJ/MNRAS/495/1888/table5Models of the eight target stars, fitting their observed values of effective temperature, luminosity, and rotational velocityZMetallicityphys.abund.ZfloatNameStar name (HD NNNNNN)meta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintESEvolutionary stage (1)meta.code.classcharXiniInitial Hydrogen abundancephys.abund.XfloatfovExtent of overshootingstat.paramfloatVrotiniInitial rotational velocity on the zero-age main sequencekm/sphys.veloc.rotat;meta.mainintVrotCurrent rotational velocitykm/sphys.veloc.rotatintMassStellar masssolMassphys.massfloatAgeStar ageyrtime.agedoubleRadStar radiussolRadphys.size.radiusfloatloggSurface gravitylog(cm.s**-2)phys.gravityfloatJ/MNRAS/495/1888/tablea1Known pulsation properties of {lambda}Boo stars from the literaturerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar name (HD NNNNNN)meta.id;meta.maincharFreqFrequencyd**-1em.freqfloatAmplAmplitudemmagphot.magfloatFilterFiltermeta.id;instr.filtercharRefReferencemeta.ref;pos.framechar