J/A+A/674/A146ivo://CDS.VizieR/J/A+A/674/A146doi:10.26093/cds/vizier.36740146CDSPalakkatharappil D.B.Creevey O.L.2024-11-28T20:03:37Z2023-06-15T07:18:38ZCDS support team

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

cds-question@unistra.fropen-star-clustersccd-photometryvariable-starsAsteroseismology is one of the few methods to derive ages of individual stars due to the high precision of their observations. Isochrone fitting is a powerful alternative method for deriving ages by studying clusters of stars. Pulsating stars in clusters should therefore allow for detailed studies of the stellar models. Our objectives are to exploit the NASA TESS data along with ESA Gaia data to search for and detect oscillations in cluster member stars. We analyse the intermediate-age open cluster NGC 2477, known to suffer from differential extinction, to explore if asteroseismology and cluster characteristics can help us understand the metallicity and extinction, as well as result in better age determinations than isochrone-fitting alone. We combined a multitude of recent observations from Gaia, high-resolution spectroscopy, and extinction maps to analyse the cluster and then search for and detect variability in the member stars using TESS full frame images (FFIs) data. To interpret all of these data, we used stellar structure, evolution and oscillation codes. We conducted an in-depth analysis of the extinction and metallicity of NGC 2477, using the most recent spectroscopic, photometric, and extinction observations for the cluster. Analysis of dust and extinction maps confirmed that the differential extinction in the direction of the cluster is not due to the background. The cluster's metallicity from high-resolution spectroscopy varies from 0.06 to 0.16dex. We performed an isochrone fitting to the cluster using publically available isochrones (BASTI, MIST, and PARSEC), which provides a cluster age of between 0.6 to 1.1Ga. Then using TESS FFI, we analysed the time dimension of the members of this cluster. We created optimised pixel light curves using the tessipack package which allows us to consider possible contamination by nearby stars. Using these light curves, we identified many interesting levels of variability of stars in this cluster, including binaries and oscillating stars. For the asteroseismic analysis, we selected a few uncontaminated A-F type oscillating stars and used the MESA and GYRE codes to interpret the frequency signals. By comparing the theoretical and the observed spectra, we identified frequency separations, {DELTA}{nu}, for four stars. Then using the identified {DELTA}{nu} and imposing that the best matched theoretical models have the same age, metallicity, and background extinction, we constrained the cluster's age to 1.0+/-0.1Ga. We conclude that using the TESS FFI data, we can identify oscillating stars in clusters and constrain the age of the cluster using asteroseismology.2023A&A...674A.146Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/674/A146CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/674/A146https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/674/A146http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/674/A146https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/674/A146https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/674/A146http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/674/A146GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/674/A146/table1 (Position, magnitude, membership probability and variability of stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/674/A146/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/674/A146/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/674/A146/table1?GETtext/xml+votable180.050000true118.079-38.4730.0055555555555555566/39347 39350 39353 393561.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/674/A146?format=asciidefaultJ/A+A/674/A146/table1Position, magnitude, membership probability and variability of starsSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentification for each star (N77-NNNN)meta.id;meta.maincharGaiaDR2Gaia DR2 source identificationmeta.idRA_ICRSRight ascension (ICRS) at Ep=2015.5degpos.eq.ra;meta.mainDE_ICRSDeclination (ICRS) at Ep=2015.5degpos.eq.dec;meta.mainGmagGaia G magnitudemagphot.mag;em.optfloatBP-RP? Gaia BP-RP colourmagphot.color;em.opt.B;em.opt.RfloatnullablePMembMembership Probability (1)stat.probabilitydoubleCode[OBDRU ] Type of variability (2)meta.notecharMore[*] * indicates data in table A1, lc and prmeta.codecharLCShow the light curvemeta.ref.urlcharPRShow the periodogrammeta.ref.urlcharJ/A+A/674/A146/tablea1Identified individual frequencies for oscillating starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar identification (N77-NNN)meta.id;meta.maincharFreqFrequencyuHzem.freqfloatS/NSignal to Noise ratiostat.snrfloatfdetThe fraction of times that the signal is above the S/Nstat.fit.paramfloat