J/A+A/703/A128ivo://CDS.VizieR/J/A+A/703/A128doi:10.26093/cds/vizier/bc-nz/lbciCDSBale B.Tautvaisiene G.Minkeviciute R.Drazdauskas A.Mikolaitis S.,Stonkute E.Ambrosch M.2026-08-03T06:59:01Z2025-11-13T09:13:46ZCDS support team

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

cds-question@unistra.frvariable-starsmagnetic-fieldschemical-abundancesWe carried out a detailed investigation of Lthium and CNO abundances, including carbon isotope ratios, in RS CVn stars to assess the role of magnetic activity in the mixing of stellar atmospheres. High-resolution spectra were observed at the Moletai Astronomical Observatory to determine the lithium abundances by spectral synthesis of the 6707{AA} line and the CNO abundances using the C2 band heads at 5135 and 5635.5{AA}, CN bands at 6470-6490{AA} and 7980-8005{AA}, and the [O I] line at 6300{AA}. By fitting the ^13^CN band at 8004.7{AA}, we determined the carbon isotope ratios. We determined the main atmospheric parameters and investigated the chemical composition for 32 RS CVn stars. Lithium NLTE abundances were determined for 13 additional stars using archival spectra. We found that iota Gem and HD 179094 have carbon isotope ratios already affected by extra-mixing, even though being in the evolutionary stage below the red giant branch luminosity bump. About half of the low-mass giants, for which the lithium abundance was determined, follow the first dredge-up predictions; however, other stars have Li abundances reduced as predicted by the thermohaline-induced mixing. The intermediate-mass stars have Li abundances reduced as predicted by the rotation-induced mixing. We found that in low-mass chromospherically active RS CVn stars extra mixing of lithium along with carbon isotopes may begin earlier than in normal giants. The Li-rich RS CVn giant V* OP And has quite large C/N and carbon isotope ratios, and raises questions about the origin of its lithium enhancement.2025A&A...703A.128Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/703/A128CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/703/A128https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/703/A128http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/703/A128https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/703/A128https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/703/A128http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/703/A128GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/703/A128/tablea1 (Atmospheric parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/703/A128/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/703/A128/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/703/A128/tablea1?GETtext/xml+votable180.050000true1.3339217-5.707620.005555555555555556Cone search capability for table J/A+A/703/A128/tablea2 (Lithium abundances)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/703/A128/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/703/A128/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/703/A128/tablea2?GETtext/xml+votable180.050000true1.3339217-5.707620.0055555555555555566/1495 2839 2927 3579 4559 4772 5024 5028 5670 5676 6203 6219 6241 7451 8378 8667 8844-8845 8937 9541 10241 10407 10490 11764 12143 12155 12962 13462 13778 14020 14596 14630 15165 15409 17368 17989 18417 20102 22909 26302 27088 28252 29923 30431 32743https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/703/A128?format=asciidefaultJ/A+A/703/A128/tablea1Atmospheric parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDTycho-2 catalogue identificationmeta.id;meta.maincharNameStellar namemeta.idcharResSpectral resolutionspect.resolutionintTeffEffective temperatureKphys.temperature.effectiveinte_TeffUncertainity in effective temperatureKstat.error;phys.temperature.effectiveintloggStellar surface gravitylog(cm.s**-2)phys.gravityfloatSimbadSimbad column added by the CDSmeta.ref.urlchare_loggUncertainity in stellar surface gravitylog(cm.s**-2)stat.errorfloat[Fe/H]Metallicityphys.abund.Zfloate_[FeI/H]Uncertainity in [Fe I/H]stat.error;phys.abundfloato_FeINumber of Fe I linesmeta.numberinte_[FeII/H]Uncertainity in [Fe II/H]stat.error;phys.abundfloato_FeIINumber of Fe II linesmeta.numberintVtMicroturbulence velocitykm/sphys.veloc.microTurbfloate_VtUncertainity in microturbulence velocitykm/sstat.errorfloat[C/H]? Carbon abundancephys.abundfloatnullablee_[C/H]? Uncertainity in carbon abundancestat.error;phys.abundfloatnullableo_C? Number of C2 linesmeta.numberintnullable[N/H]? Nitrogen abundancephys.abundfloatnullablee_[N/H]? Uncertainity in nitrogen abundancestat.error;phys.abundfloatnullableo_N? Number of CN linesmeta.numberintnullable[O/H]? Oxygen abundancephys.abundfloatnullablee_[O/H]Uncertainity in oxygen abundancestat.error;phys.abundfloato_ONumber of oxygen linesmeta.numberint[Mg/H]Magnesium abundancephys.abundfloate_[Mg/H]Uncertainity in magnesium abundancestat.error;phys.abundfloato_MgNumber of magnesium linesmeta.numberfloat12C/13C? Carbon isotope ratiophys.abundintnullablee_12C/13C? Uncertainity in carbon isotope ratiostat.errorintnullableC/N? Carbon-to-nitrogen abundance ratiophys.abundfloatnullableMassStellar masssolMassphys.massfloate_MassUncertainity of masssolMassstat.error;phys.massfloatEvolEvolutionary stage (1)meta.notecharEm[YES -] YES if emission is visible in the CaII linesmeta.codechar_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/A+A/703/A128/tablea2Lithium abundancesNameStellar namemeta.idcharSimbadSimbad column added by the CDSmeta.ref.urlchar_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.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDTycho-2 catalogue identificationmeta.id;meta.maincharResSpectral resolutionspect.resolutionintA(Li)LTE? Lithium abundance in LTEphys.abundfloatnullableA(Li)NLTE? Lithium abundance in NLTEphys.abundfloatnullablee_A(Li)? Uncertainity in lithium abundancestat.errorfloatnullablel_A(Li)[0/1]? Limit flag on A(Li) (1 for upper limit)meta.code.errorintnullable