J/MNRAS/386/2039ivo://CDS.VizieR/J/MNRAS/386/2039doi:10.26093/cds/vizier.73862039CDSBruntt H.North J.R.Cunha M.Brandao I.M.Elkin V.G.Kurtz D.W.,Davis J.Bedding T.R.Jacob A.P.Owens S.M.Robertson J.G.Tango W.J.,Gameiro J.F.Ireland M.J.Tuthill P.G.2024-07-06T20:16:04Z2009-09-14T18:02:00ZCDS support team

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

cds-question@unistra.frvariable-starsspectroscopychemical-abundancesWe have used the Sydney University Stellar Interferometer to measure the angular diameter of alpha Cir. This is the first detailed interferometric study of a rapidly oscillating A (roAp) star, alpha Cir being the brightest member of its class. We used the new and more accurate Hipparcos parallax to determine the radius to be 1.967+/-0.066R_{sun}_. We have constrained the bolometric flux from calibrated spectra to determine an effective temperature of 7420+/-170K . This is the first direct determination of the temperature of an roAp star. Our temperature is at the low end of previous estimates, which span over 1000K and were based on either photometric indices or spectroscopic methods. In addition, we have analysed two high-quality spectra of alpha Cir, obtained at different rotational phases and we find evidence for the presence of spots.2008MNRAS.386.2039Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/386/2039CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/386/2039https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/386/2039http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/386/2039https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/386/2039https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/386/2039http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/386/2039GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/MNRAS/386/2039/table6Abundance of alpha Cir relative to the Sun based on the analysis of the spectrum from 2004recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElElementphys.atmol.elementcharn_El[a] Note on Nd (1)meta.notecharA0? Mean abundance of neutral line (2)log(Sun)phys.abundfloatnullablee_A0? rms uncertainty on AIlog(Sun)stat.errorfloatnullableN0? Number of neutral linesmeta.numberintnullableA+? Mean abundance of ionized line (2)log(Sun)phys.abundfloatnullablee_A+? rms uncertainty on AIIlog(Sun)stat.errorfloatnullableN+? Number of ionized linesmeta.numberintnullableJ/MNRAS/386/2039/table5*The atomic number, element name, wavelength, and oscillator strength from the VALD database for lines used in the abundance analysisrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintZAtomic numbermeta.id;meta.mainintIonElement and Ionization levelphys.atmol.element;phys.atmol.level;phys.atmol.ionizationcharlambdaWavelength0.1nmem.wldoubleloggfOscillator strengthphys.atmol.oscStrengthfloat