J/A+A/622/A133ivo://CDS.VizieR/J/A+A/622/A133doi:10.26093/cds/vizier.36220133CDSIlin E.Schmidt S.J.Davenport J.R.A.Strassmeier K.G.2021-02-22T12:55:27Z2019-02-07T09:57:46ZCDS support team

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

cds-question@unistra.fropen-star-clustersstellar-flaresvisible-astronomysloan-photometryinfrared-photometryThe presence and strength of a stellar magnetic field and activity is rooted in a star's fundamental parameters such as mass and age. Can flares serve as an accurate stellar "clock"? To explore if we can quantify an activity-age relation in the form of a flaring-age relation, we measured trends in the flaring rates and energies for stars with different masses and ages. We investigated the time- domain photometry provided by Kepler's follow-up mission K2 and searched for flares in three solar metallicity open clusters with well-known ages, M45 (0.125Gyr), M44 (0.63Gyr), and M67 (4.3Gyr). We updated and employed the automated flare finding and analysis pipeline Appaloosa, originally designed for Kepler. We introduced a synthetic flare injection and recovery subroutine to ascribe detection and energy recovery rates for flares in a broad energy range for each light curve. We collected a sample of 1761 stars, mostly late-K to mid-M dwarfs and found 751 flare candidates with energies ranging from 4x10^32^erg to 6x10^34^erg, of which 596 belong to M45, 155 to M44, and none to M67. We find that flaring activity depends both on Teff, and age. But all flare frequency distributions have similar slopes with alpha from 2.0 to 2.4, supporting a universal flare generation process. We discuss implications for the physical conditions under which flares occur, and how the sample's metallicity and multiplicity affect our results.2019A&A...622A.133Ihttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/622/A133CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)J/ApJ/795/161 : Activity and rotation in Praesepe and Hyades (Douglas+ 2015)J/AJ/152/113 : Pleiades members with K2 light curves. I. PeriodsJ/MNRAS/459/1060 : M67 variable stars from Kepler/K2-Campaign-5 (Gonzalez 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/622/A133https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/622/A133http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/622/A133https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/622/A133https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/622/A133http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/622/A133GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/622/A133/cparam (Power law fits to bin-wise flare frequency distributions)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/622/A133/cparam?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/622/A133/cparam?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/622/A133/cparam?GETtext/xml+votable180.050000true129.0605338915.919901110.0055555555555555564/28 5/91 94 116 118 120 1169 1171 1173-1175 1177 1180-1181 6/319 355 358-359 361 363 370-371 380-382 405 407 409 412 415 437 468 470-471 476-478 484-486 496 4335 4346-4347 4351 4673-4675 4680 4682-4683 4689-4691 4704-4705 4707 4713 4716-4717 4728-4730 4732-4734 4816-4817 4872-4874 4896 48988.650015785639275e-20 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/622/A133?format=asciiOpticalInfrareddefaultJ/A+A/622/A133/alphabetStellar parameters for M44 and M45 membersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterCluster designationmeta.id.parentcharTminMinimum Teff in binKphys.temperature.effectiveintTmaxMaximum Teff in binKphys.temperature.effectiveintnLCNumber of light curves in binmeta.numberintnflaresNumber of flares in binmeta.numberintalphaPower law exponent Eq. (12) of the paperarith.factor;phys.luminositydoublee_alphaPower law exponent uncertaintystat.error;pos.eq.radoublelog10betaPower law factor Eq. (12) of the paperarith.factor;phys.luminositydoublee_log10betaPower law factor uncertainty Eq. (12) of the paperstat.errordoublelog10beta2Power law factor Eq. (12) of the paper with alpha fixed at 2arith.factor;phys.luminositydoubleE_log10beta2Power law factor upper uncertainty Eq. (12) of the paper with alpha fixed at 2stat.error;stat.maxdoublee_log10beta2Power law factor upper uncertainty Eq. (12) of the paper with alpha fixed at 2stat.errordoubledetthreshMinimum Kepler flare energy in bin1e-07Jphys.energydoubleJ/A+A/622/A133/cparamPower law fits to bin-wise flare frequency distributionst? Total observing timedtime.durationdoublenullablewhydropReason why light curve was droppedmeta.notecharEPICK2 IDmeta.id;meta.mainlongprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFlareindicates indices into light curves to find flares in table allflaremeta.ref.urlcharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainCampaignK2 Campaignmeta.noteintSpClassDwarf spectral classsrc.spTypecharTeffEffective temperatureKphys.temperature.effectiveinte_TeffUncertainty of effective temperatureKstat.error;phys.temperature.effectivedoublelogTefflog10 effective temperature as in Pecaut and Mamajek (2013, Cat. J/ApJS/208/9)log(K)phys.temperature.effectivefloatlogLlog10 luminosity as in Pecaut and Mamajek (2013, Cat. J/ApJS/208/9)log(1e-07W)phys.luminosityfloatJmag2MASS J band magnitudemagphot.mag;em.IR.JfloatKsmag2MASS Ks band magnitudemagphot.mag;em.IR.KfloatmbolBolometric magnitude as in Pecaut and Mamajek (2013, Cat. J/ApJS/208/9)magphot.mag.bolfloate_mbolUncertainty on bolometric magnitudemagstat.errordoubleRadStellar radius as in Pecaut and Mamajek (2013, Cat. J/ApJS/208/9)solRadphys.size.radiusfloate_RadUncertainty on stellar radiussolRadstat.errorfloatu-g? SDSS u-g color indexmagphot.color;em.opt.U;em.opt.Bfloatnullableg-r? SDSS g-r color indexmagphot.color;em.opt.B;em.opt.Rfloatnullabler-i? SDSS r-i color indexmagphot.color;em.opt.R;em.opt.Ifloatnullablei-z? SDSS i-z color indexmagphot.color;em.opt.I;em.opt.Ifloatnullablez-J? SDSS-2MASS z-J color indexmagphot.color;em.opt.I;em.IR.JfloatnullableJ-H? 2MASS J-H color indexmagphot.color;em.IR.J;em.IR.HfloatnullableH-K? 2MASS H-K color indexmagphot.color;em.IR.H;em.IR.KfloatnullableJMAG? Absolute J magnitude as in Pecaut and Mamajek (2013, Cat. J/ApJS/208/9)magphys.magAbsfloatnullableLquiet? Quiescent Kepler luminosity1e-07Wphys.luminositydoublenullablee_Lquiet? Quiescent Kepler luminosity uncertainty1e-07Wstat.errordoublenullableLquietbolQuiescent bolometric luminosity1e-07Wphys.luminositydoublee_LquietbolQuiescent bolometric luminosity uncertainty1e-07Wstat.errordoubletodrop[0/1] Light curve was dropped, yes is 1meta.codeintnappaflares? Number of flare in light curvemeta.numberintnullableClusterCluster designationmeta.id.parentcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/622/A133/allflareIndices into light curves to find flaresTeffEffective temperatureKphys.temperature.effectiveintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEPICK2 IDmeta.id;meta.mainlongClusterCluster designationmeta.id.parentcharEkpflareKepler flare energyergphys.energydoublee_EkpflareKepler flare energy uncertaintyergstat.errordoublestartFlare start index into K2SC light curvemeta.codeintstopFlare stop index into K2SC light curvemeta.codeint