J/A+A/690/A125ivo://CDS.VizieR/J/A+A/690/A125doi:10.26093/cds/vizier.36900125CDSBeguin E,. Chiavassa A.Ahmad A.Freytag B.Uttenthaler S.2025-02-27T20:01:47Z2024-12-24T11:01:28ZCDS support team

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

cds-question@unistra.frgiant-starsvisible-astronomytrigonometric-parallaxastronomical-modelseffective-temperatureThe complex dynamics of asymptotic giant branch (AGB) stars and the resulting stellar winds have a significant impact on the measurements of stellar parameters and amplify their uncertainties. Three-dimensional (3D) radiative hydrodynamic (RHD) simulations of convection suggest that convection-related structures at the surface of AGB star affect the photocentre displacement and the parallax uncertainty measured by Gaia. We explore the impact of the convection on the photocentre variability and aim to establish analytical laws between photocentre displacement and stellar parameters to retrieve such parameters from the parallax uncertainty. We used a selection of 31 RHD simulations with CO5BOLD and the post-processing radiative transfer code Optim3D to compute intensity maps in the Gaia G band [320-1050nm]. From these maps, we calculated the photocentre position and temporal fluctuations. We then compared the synthetic standard deviation to the parallax uncertainty of a sample of 53 Mira stars observed with Gaia. The simulations show a displacement of the photocentre across the surface ranging from 4 to 13% of the corresponding stellar radius, in agreement with previous studies. We provide an analytical law relating the pulsation period of the simulations and the photocentre displacement as well as the pulsation period and stellar parameters. By combining these laws, we retrieve the surface gravity, the effective temperature, and the radius for the stars in our sample. Our analysis highlights an original procedure to retrieve stellar parameters by using both state-of-the-art 3D numerical simulations of AGB stellar convection and parallax observations of AGB stars. This will help us refine our understanding of these giants.2024A&A...690A.125Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/690/A125CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/A+A/622/A120 : Mass loss from Miras with and without Tc (Uttenthaler, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/690/A125https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/690/A125http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/690/A125https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/690/A125https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/690/A125http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/690/A125GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/690/A125/tablea2 (Parameters of the Miras)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/690/A125/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/690/A125/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/690/A125/tablea2?GETtext/xml+votable180.050000true24.903704239.34302970.005555555555555556Cone search capability for table J/A+A/690/A125/tablea3 (Stellar parameters of the Miras inferred from the simulations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/690/A125/tablea3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/690/A125/tablea3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/690/A125/tablea3?GETtext/xml+votable180.050000true24.903704239.34302970.0055555555555555566/220 1345 2464 4892 5647 6451 9091 9755 11214 11823 11997 12501 12833 13080 13566 15359 19293 19624 20272 20636 22333 22369 22497 26360 28740 29017 29387 30062 30207 30661 31764 32234 32384 32622 33740 34292 36120 36124 36738 37023 37263 37994 40240 41001 42052 44309 44396 44546 45524 47293 47749 48575 49123https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/690/A125?format=asciiOpticaldefaultJ/A+A/690/A125/tablea1RHD simulation parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIdModel identification number (1)meta.idintSimSimulation namemeta.id;stat.fitcharM*Stellar masssolMassphys.massfloatL*Average emitted luminositysolLumphys.luminosityintR*Average approximate stellar radiussolRadphys.size.radius;stat.meanintTeffEffective temperatureKphys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloattavgStellar time used for the averaging of the rest of the quantitiesyrtime.epochfloatPPulsation perioddtime.periodinte_PPulsation period errordstat.errorintPxTime-averaged position Pxaupos.cartesian.x;instr.detfloatn_Px[a] Note on Px (2)meta.notecharPyTime-averaged position Pyaupos.cartesian.y;instr.detfloatn_Py[a] Note on Px (2)meta.notecharsigPStandard deviation of the photocentre displacement in AUaustat.stdevfloatn_sigP[a] Note on Px sigP (2)meta.notecharsipPpStandard deviation of the photocentre displacement in percentage of stellar radiusstat.stdevfloatn_sipPp[a] Note on Px (2)meta.notecharJ/A+A/690/A125/tablea2Parameters of the MirasE_L*Positive luminosity uncertaintysolLumstat.error;stat.maxintplxGaia DR3 parallaxmaspos.parallax.trigfloatplxcorrCorrected Gaia DR3 parallax according to Lindegren et al. (2021A&A...649A...4L)maspos.parallax.trigfloate_plxParallax uncertaintymasstat.error;pos.parallaxfloatPopPopulation membership based on a study of stellar total space velocity according to Chen et al. (2021ApJ...909..115C), halo stars are more metal poormeta.codecharSimbadSimbad 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.recordintNameMiras' namemeta.id;meta.maincharPobsPulsation period obtained from light curves (1)dtime.periodintRUWERUWEstat.errorfloatNperNumber of visibility periods used in the astrometric solution (2)meta.numberintNgoodTotal number of good observations along-scan (astrometric_n_good_obs_al) by Gaia to compute the astrometric solutionmeta.numberintL*LuminositysolLumphys.luminosityinte_L*Negative luminosity uncertaintysolLumstat.errorintJ/A+A/690/A125/tablea3Stellar parameters of the Miras inferred from the simulationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the Mira starmeta.id;meta.maincharPobsPulsation period (1)dtime.periodintRUWEGoodness of the astrometry fit from Gaia DR3stat.errorfloatNperNb of visibility periods for astrometry from Gaia DR3meta.numberintNgoodTotal nb of good observations along-scan from Gaia DR3meta.numberintL*Computed luminosity value (2)solLumphys.luminosityinte_L*Negative luminosity uncertainty (2)solLumstat.errorintE_L*Positive luminosity uncertainty (2)solLumstat.error;stat.maxintplxGaia DR3 parallaxmaspos.parallax.trigfloatplxcorrCorrected parallax, see Lindegren et al., 2021A&A...649A...4Lmaspos.parallax.trigfloate_plxGDR3 parallax uncertaintymasstat.error;pos.parallaxfloatPopPopulation membership, see Chen et al., 2021ApJ...909..115C, Cat. J/ApJ/909/115meta.codecharP10Pulsation period inferred from simulations at 1.0M_{sun}_dtime.periodintDP10Relative difference between Pobs and P10%stat.fit.paramintP15Pulsation period inferred from simulations at 1.5M_{sun}_dtime.periodintDP15Relative difference between Pobs and P15%stat.fit.paramintlogg10Surface gravity from simulations at 1.0M_{sun}_log(cm.s**-2)phys.gravityfloatlogg15Surface gravity from simulations at 1.5M_{sun}_log(cm.s**-2)phys.gravityfloatR10Radius inferred from simulations at 1.0M_{sun}_solRadphys.size.radiusintR15Radius inferred from simulations at 1.5M_{sun}_solRadphys.size.radiusintTeff10Effective temperature from simulations at 1.0M_{sun}_Kphys.temperature.effectiveintTeff15Effective temperature from simulations at 1.5M_{sun}_Kphys.temperature.effectiveintSimbadSimbad 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.main