J/A+AS/124/359ivo://CDS.VizieR/J/A+AS/124/359CDSMallik S.V.1997-12-09T18:38:01Z1997-12-09T19:37:57ZCDS support team

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

cds-question@unistra.frlate-type-starsstellar-atmospheresline-intensitiesspectroscopyCCD spectra of the infrared triplet lines of ionized calcium at {lambda}{lambda}8498, 8542, 8662 have been obtained at a spectral resolution of 0.4{AA} in 146 stars brighter than V=+7.0 spanning a range in spectral types from F7 to M4 of all luminosity classes and a range in metallicity [Fe/H] from -3.0 to +1.1. These have been analysed to investigate the dependence of the Ca II triplet strengths on stellar parameters like luminosity, temperature and metallicity. A detailed study reveals a strong dependence on luminosity, much stronger for metal rich stars than for the metal poor ones and a milder dependence on metallicity, although much more conspicuous in supergiants than in dwarfs. All these correlations are found to be non-linear over the parameter space covered. The present study also shows chromospheric activity to be an important phenomenon affecting the strength and the shape of the line profiles. Stars of similar luminosity and metallicity have varying Ca II line depths owing to varying chromospheric emission filling in their Ca II absorption. The Ca II triplet strength is thus observed to be a triparametric discriminant in cool stars.1997A&AS..124..359Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+AS/124/359CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+AS/124/359https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+AS/124/359http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+AS/124/359https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+AS/124/359https://vizier.iucaa.in/viz-bin/votable?-source=J/A+AS/124/359http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+AS/124/359GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+AS/124/359/table1Stellar parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHDHD number, Cat. <III/135>meta.id;meta.mainintHR? HR number, Cat. <V/50>meta.idintNameStar namemeta.idcharVmagV magnitudemagphot.mag;em.opt.VfloatSpTypeSpectral typesrc.spTypecharTeff? Effective temperatureKphys.temperature.effectivefloatR-I? R-I color indexmagphot.color;em.opt.R;em.opt.Ifloatlogg? Gravity surfacelog(cm.s**-2)phys.gravityfloatn_logg[*] Note on logg (1)meta.notechar[Fe/H]? Metallicitylog(Sun)phys.abund.FefloatJ/A+AS/124/359/table2Measured line strengths of the Ca II tripletrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHDHD number, Cat. <III/135>meta.id;meta.mainintHR? HR number, Cat. <V/50>meta.idintNameStar namemeta.idcharEW8498Equivalent width at lambda84980.1nmspect.line.eqWidthfloatEW8542Equivalent width at lambda85420.1nmspect.line.eqWidthfloatEW8662Equivalent width at lambda86620.1nmspect.line.eqWidthfloatEWallSum of EWs of all the three lines0.1nmspect.line.eqWidthfloatEW8542+EW8662Sum of EWs of lambda8542 and lambda86620.1nmspect.line.eqWidthfloat