J/A+A/678/A104ivo://CDS.VizieR/J/A+A/678/A104doi:10.26093/cds/vizier.36780104CDSMolnar L.Plachy E.Bodi A.Pal A.Joyce M.Kalup Cs.Johnson C.I.,Dencs Z.Meszaros Sz.Netzel H.Kinemuchi K.Kollmeier J.A.,Prieto J.L.Derekas A.2025-05-06T20:00:57Z2023-10-12T08:25:44ZCDS support team

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

cds-question@unistra.frglobular-star-clustersvariable-starsphotometryvisible-astronomyspectroscopyThe globular cluster Messier 80 was monitored by the Kepler space telescope for 80 days during the K2 mission. Continuous, high-precision photometry of such an old, compact cluster allows us to study its variable star population in unprecedented detail. We extract light curves for 27 variable stars using differential-image photometry. A search for new variables in the images led to the discovery of two new variable stars: an RR Lyrae and a variable red giant star, respectively. Analysis of the RR Lyrae population reveals multiple RRc stars with additional modes and/or peculiar modulation cycles. We newly classify star V28 as a spotted extreme horizontal branch variable. Despite their faintness, we clearly detect the three SX Phe stars but we did not find new pulsation modes beyond the known ones in them. Spectra taken with the VLT and Magellan Clay telescopes, as well as absolute color-magnitude diagrams of the cluster based on Gaia and Pan-STARRS observations confirm the classification of the peculiar modulated variables as bona-fide RRc stars. We propose that they highlight a subgroup of overtone stars that may have been overlooked before. We fit MESA isochrones to the CMDs to estimate the age and metallicity of the cluster. We confirm that M80 is old and metal-poor, but show that isochrone fitting to old populations comes with numerous uncertainties.2023A&A...678A.104Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/678/A104CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AcA/63/91 : V-band light curves of variables in M80 (Kopacki, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/678/A104https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/678/A104http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/678/A104https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/678/A104https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/678/A104http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/678/A104GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/678/A104/tablea5 (Gaia absolute magnitudes, dereddened colors and zeropoint-corrected parallaxes of stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/678/A104/tablea5?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/678/A104/tablea5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/678/A104/tablea5?GETtext/xml+votable180.050000true244.219125-22.95441670.005555555555555556Cone search capability for table J/A+A/678/A104/list (List of fits spectra)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/678/A104/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/678/A104/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/678/A104/list?GETtext/xml+votable180.050000true244.292625-22.96052780.0055555555555555566/42990https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/678/A104?format=asciiOpticaldefaultJ/A+A/678/A104/tablea5Gaia absolute magnitudes, dereddened colors and zeropoint-corrected parallaxes of starsLCShow the K2 light curvemeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypeType of variable (other for other variable)meta.code;src.varcharIDVariable ID as in table A1meta.idcharprimaryGaiaDR3Gaia DR3 IDmeta.idGMAGAbsolute G magnitudemagphys.magAbsfloat(BP-RP)0? Dereddened BP-RP colour indexmagphot.color;em.opt.B;em.opt.Rfloatnullablee_GMAGAbsolute G magnitude errormagstat.errorfloate_(BP-RP)0? Dereddened BP-RP colour index errormagstat.errorfloatnullableplx? Zeropoint-corrected parallaxmaspos.parallaxfloatnullablee_plx? Zeropoint-corrected parallax errormasstat.error;pos.parallaxfloatnullableNameVariable namemeta.id;meta.maincharRAJ2000Simbad right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Simbad declination (J2000)pos.eq.dec;meta.mainPer? Period (from table A2)dtime.perioddoublenullablespindicates spectrum in list.dat filemeta.ref.urlcharJ/A+A/678/A104/listList of fits spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentification of the starmeta.id;meta.maincharRAJ2000Simbad right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Simbad declination (J2000)pos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNy? Number of pixels along Y-axismeta.numberintnullableObs.dateObservation datestime.epoch;obsnullablebLAMBDALower value of wavelength interval0.1nmem.wlintBLAMBDAUpper value of wavelength interval0.1nmem.wlintsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitscharspShow the spectrummeta.ref.urlcharJ/A+A/678/A104/tablea1M80 light curvesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentification of the starmeta.id;meta.maincharBJDKepler Barycentric Julian Date (BJD-2454833.0)dtime.epochdoubleindexedKpmagBrightness in the Kepler passbandmagphot.magdoublee_KpmagBrightness uncertaintymagstat.error;phot.magdoubleFluxMeasured flux in the Kepler passbande.s**-1phot.flux.density;em.optdoublee_FluxFlux uncertaintye.s**-1stat.error;phot.fluxfloat