J/A+A/696/A23ivo://CDS.VizieR/J/A+A/696/A23doi:10.26093/cds/vizier/bc-nr/lcdCDSBale B.Tautvaisiene G.Minkeviciute R.Drazdauskas A.Mikolaitis S.,Stonkute E.Ambrosch M.2026-02-10T20:02:37Z2025-03-28T07:44:06ZCDS support team

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

cds-question@unistra.frvariable-starschemical-abundancesspectroscopyVarious element transport processes modify the photospheric chemical composition of low-mass stars during their evolution. The most prominent one is the first dredge-up that occurs at the beginning of the red giant branch. Then, various extra-mixing processes, e.g. caused by thermohaline- or and rotation-induced mixing, come into action. The extent of influence of stellar magnetic activity on alterations of stellar chemical composition is among the least studied questions. To investigate how magnetic activity influences mixing in atmospheres of magnetically active stars, we carried out a detailed study of C, N, and up to ten other chemical element abundances, as well as carbon isotope ratios in a sample of RS,CVn stars. High-resolution spectra, observed with the VUES spectrograph on the 1.65m telescope at the Moletai Astronomical Observatory of Vilnius University, were analyzed using a differential model atmosphere method. Abundances of carbon were derived using the spectral synthesis of the C_2 band heads at 5135 and 5635.5{AA}. The wavelength intervals 6470-6490{AA} and 7980-8005{AA} with CN features, was analyzed to determine nitrogen abundances. The carbon isotope ratios were determined from the 13 CN line at 8004.7{AA}. Oxygen abundances were determined from the [OI] line at 6300{AA}. Abundances of other chemical elements were determined from equivalent widths or spectral syntheses of unblended spectral lines. We determined the main atmospheric parameters and abundances of up to 12 chemical elements for a sample of 20 RS CVn giants representing different evolutionary stages. We determined that *29 Dra, *b01 Cyg, and V* V834 Her, which are in the evolutionary stage below the red giant branch luminosity bump, already show the extra-mixing evidences in their lowered carbon isotope ratios. We provide observational evidence that in low-mass chromospherically active RS CVn stars due to their magnetic activity the extra-mixing processes may start acting below the luminosity bump of the red giant branch.2025A&A...696A..23Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/696/A23CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/696/A23https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/696/A23http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/696/A23https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/696/A23https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/696/A23http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/696/A23GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/696/A23/tablea1 (Stellar physical and chemical properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/696/A23/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/696/A23/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/696/A23/tablea1?GETtext/xml+votable180.050000true19.1511997-2.50036920.0055555555555555566/1495 1938 3579 4191 4559 4574 5670 10407 11764 12143 13462 14297 14628 14630 15409 17989 18417 30431 31966 32664https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/696/A23?format=asciidefaultJ/A+A/696/A23/tablea1Stellar physical and chemical propertiesn_TiINumber of [TiI/H] linesmeta.noteinte_12C/13C? Uncertainty in carbon isotope ratiostat.errorintnullableSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintResSpectral resolutionspect.resolutionintTeffEffective temperatureKphys.temperature.effectiveinte_TeffUncertainty in effective temperatureKstat.error;phys.temperature.effectiveintloggStellar surface gravitylog(cm.s**-2)phys.gravityfloate_loggUncertainty in stellar surface gravitylog(cm.s**-2)stat.errorfloat[Fe/H]Metallicityphys.abundfloate_FeIUncertainty in [FeI/H]stat.errorfloatn_FeINumber of FeI linesmeta.noteinte_FeIIUncertainty in [FeII/H]stat.errorfloatn_FeIINumber of FeII linesmeta.noteintVtMicroturbulence velocitylog(km.s**-1)phys.veloc.microTurbfloate_VtUncertainty in microturbulence velocitylog(km.s**-1)stat.errorfloat[C/H]Carbon abundancephys.abundfloate_[C/H]Uncertainty in carbon abundancestat.error;phys.abundfloatn_CNumber of C2 linesmeta.noteint[N/H]Nitrogen abundancephys.abundfloate_[N/H]Uncertainty in nitrogen abundancestat.error;phys.abundfloatn_NNumber of CN linesmeta.noteint[O/H]Oxygen abundancephys.abundfloate_[O/H]Uncertainty in oxygen abundancestat.error;phys.abundfloatn_ONumber of oxygen linesmeta.noteint[Mg/H]Magnesium abundancephys.abundfloate_[Mg/H]? Uncertainty in magnesium abundancestat.error;phys.abundfloatnullablen_MgNumber of magnesium linesmeta.noteint[Si/H]Silicon abundancephys.abundfloate_[Si/H]Uncertainty in silicon abundancestat.error;phys.abundfloatn_SiNumber of silicon linesmeta.noteint[Ca/H]Calcium abundancephys.abundfloate_[Ca/H]Uncertainty in calcium abundancestat.error;phys.abundfloatn_CaNumber of calcium linesmeta.noteint[ScI/H]Scandium abundance from neutral linesphys.abundfloate_[ScI/H]Uncertainty in [ScI/H] abundancestat.error;phys.abundfloatn_ScINumber of [ScI/H] linesmeta.noteint[ScII/H]Scandium abundance from ionized linesphys.abundfloate_[ScII/H]Uncertainty in [ScII/H] abundancestat.error;phys.abundfloatn_ScIINumber of [ScII/H] linesmeta.noteint[TiI/H]Titanium abundance from neutral linesphys.abundfloatn_CoNumber of cobalt linesmeta.noteinte_[TiI/H]Uncertainty in [TiI/H] abundancestat.error;phys.abundfloat[TiII/H]Titanium abundance from ionized linesphys.abundfloate_[TiII/H]Uncertainty in [TiII/H] abundancestat.error;phys.abundfloatn_TiIINumber of [TiII/H] linesmeta.noteint[CrI/H]Chromium abundance from neutral linesphys.abundfloate_[CrI/H]Uncertainty in [CrI/H] abundancestat.error;phys.abundfloatn_CrINumber of [CrI/H] linesmeta.noteint[CrII/H]? Chromium abundance from ionized linesphys.abundfloatnullablee_[CrII/H]? Uncertainty in [CrII/H] abundancestat.error;phys.abundfloatnullablen_CrIINumber of [CrII/H] linesmeta.notechar[Co/H]Cobalt abundancephys.abundfloate_[Co/H]Uncertainty in cobalt abundancestat.error;phys.abundfloat[Ni/H]Nickel abundancephys.abundfloate_[Ni/H]Uncertainty in nickel abundancestat.error;phys.abundfloatn_NiNumber of nickel linesmeta.noteint12C/13C? Carbon isotope ratiospect.line.intensity;arith.ratiointnullableC/NCarbon-to-nitrogen abundance ratiospect.line.intensity;arith.ratiofloatMassStellar masssolMassphys.massfloate_MassUncertainty of masssolMassstat.error;phys.massfloatAgeStellar ageGyrtime.agefloate_AgeUncertainty of ageGyrstat.error;time.agefloatRmean? Mean galactocentric distancekpcpos.distance;stat.meanfloatnullablee_Rmean? Uncertainty of mean galactocentric distancekpcstat.errorfloatnullable_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.mainTYC-2Tycho-2 catalogue identificationmeta.idcharNameStellar starmeta.id;meta.mainchar