J/ApJ/849/36ivo://CDS.VizieR/J/ApJ/849/36doi:10.26093/cds/vizier.18490036CDSYang H.Liu J.Gao Q.Fang X.Guo J.Zhang Y.Hou Y.Wang Y.Cao Z.2018-09-27T11:27:45Z2018-07-17T13:33:02ZCDS support team

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

cds-question@unistra.frstellar-flaresm-starsdwarf-starsFlare events are mainly due to magnetic reconnection and thus are indicative of stellar activity. The Kepler Space Observatory records numerous stellar activities with unprecedented high photometric precision in flux measurements. It is perfectly suitable for carrying out a statistical study of flares. Here we present 540 M dwarfs with flare events discovered using Kepler long-cadence data. The normalized flare energy, as defined by the ratio to bolometric stellar luminosity, L_flare_/L_bol_, is used to indicate the flare activity. We find that, similar to the X-ray luminosity relation, the L_flare_/L_bol_ versus P_rot_ relation can also be described with three phases, supersaturation, saturation, and exponential decay, corresponding to an ultra- short period, a short period, and a long period. The flare activity and the number fraction of flaring stars in M dwarfs rise steeply near M4, which is consistent with the prediction of a turbulent dynamo. The size of starspots are positively correlated with flare activity. The L_flare_/L_bol_ ratio has a power-law dependence on L_H{alpha}_/L_bol_, a parameter indicative of stellar chromosphere activity. According to this relation, a small enhancement in chromosphere activity may cause a huge rise in flare energy, which suggests that superflares or hyperflares may not need an extra excitation mechanism. Through a comparison study, we suggest that flare activity is a more suitable indicator for stellar activity, especially in the boundary region. However, contrary to what is expected, some M dwarfs with strong flares do not show any light variation caused by starspots. Follow-up observations are needed to investigate this problem.2017ApJ...849...36Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/849/36CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIII/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997)V/149 : LAMOST DR2 catalogs (Luo+, 2016)V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)J/A+A/397/147 : Activity-rotation relationship in stars (Pizzolato+ 2003)J/AJ/128/426 : Subdwarfs in the SDSS (West+, 2004)J/MNRAS/390/545 : Magnetic field & velocity of early M dwarfs (Donati+, 2008)J/MNRAS/390/567 : Magnetic field and velocity of mid M dwarfs (Morin+, 2008)J/MNRAS/407/465 : Fast-rotating M dwarfs in NGC2516 (Jackson+, 2010)J/AJ/142/112 : KIC photometric calibration (Brown+, 2011)J/MNRAS/411/2099 : Fast-rotating M-dwarf stars in NGC 2547 (Jeffries+, 2011)J/AJ/141/50 : White-light flares on Kepler cool stars (Walkowicz+, 2011)J/ApJ/743/48 : Stellar rot. periods & X-ray luminosities (Wright+, 2011)J/other/Nat/485.478 : Superflares on solar-type stars (Maehara+, 2012)J/ApJ/754/4 : HST obs. of flaring stars in the Gal. bulge (Osten+, 2012)J/AJ/143/93 : Rotational velocities in early-M stars (Reiners+, 2012)J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)J/ApJ/767/95 : Improved parameters of smallest KIC stars (Dressing+, 2013)J/ApJ/771/107 : Spectroscopy of faint KOI stars (Everett+, 2013)J/ApJS/207/15 : M dwarf flare spectra (Kowalski+, 2013)J/A+A/560/A4 : Rotation periods of active Kepler stars (Reinhold+, 2013)J/ApJS/209/5 : Superflares of Kepler stars. I. (Shibayama+, 2013)J/ApJ/795/161 : Activity & rotation in Praesepe & Hyades (Douglas+, 2014)J/ApJS/211/2 : Revised properties of Q1-16 Kepler targets (Huber+, 2014)J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)J/MNRAS/447/2714 : Flare stars across the H-R diagram (Balona+, 2015)J/ApJS/220/19 : LAMOST obs. in the Kepler field. I. (De Cat+, 2015)J/ApJ/801/3 : Rotation periods for Q3-Q14 KOIs (Mazeh+, 2015)J/ApJ/812/3 : MEarth mid-to-late M dwarfs kinematics (West+, 2015)J/A+A/589/A113 : PMS stars in h Per (Argiroffi+, 2016)J/AJ/151/68 : Kepler Mission. VII. Eclipsing binaries in DR3 (Kirk+, 2016)J/ApJS/224/12 : Kepler planetary candidates. VII. 48-month (Coughlin+, 2016)J/ApJ/829/23 : Stellar flares from Q0-Q17 Kepler LCs (Davenport, 2016)J/ApJS/224/37 : White-light flares on Kepler close binaries (Gao+, 2016)http://exoplanetarchive.ipac.caltech.edu/ : NASA exoplanet archivehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/849/36https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/849/36http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/849/36https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/849/36https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/849/36http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/849/36GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/849/36/table1 (Parameters of flaring M dwarfs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/849/36/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/849/36/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/849/36/table1?GETtext/xml+votable180.050000true291.0638736.63581110.0055555555555555564/944 5/3690 3691 3694 3706 3730 3731 3732 3733 3735 3736 3737 3739 3740 3780 3782 3785 3788 3789 3792 6/14567 14573 14575 14578 14579 14581 14582 14583 14584 14585 14586 14588 14589 14591 14731 14733 14744 14746 14750 14751 14752 14754 14755 14756 14757 14759 14768 14770 14771 14772 14773 14774 14781 14782 14783 14816 14818 14819 14828 14830 14914 14915 14916 14918 14919 14936 14937 14939 14953 14954 14955 14965 14966 14967 14968 14969 14971 14972 14974 14975 15041 15044 15045 15057 15060 15061 15124 15126 15132 15133 15135 15136 15137 15139 15145 15146 15147 15148 15149 15150 15160 15172 15174 15178 15200 15232https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/849/36?format=asciidefaultJ/ApJ/849/36/table3Flare parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKIC[892376/12835232] Kepler Input Catalog identifiermeta.id;meta.mainintSt-BKJD[131.5/1591] Kepler Barycentric Julian Date start; BJD-2454833dtime.epochdoubleEd-BKJD[131.5/1591] Kepler Barycentric Julian Date end; BJD-2454833dtime.epochdoublelogEng[29.7/35.9] log flare energylog(1e-07J)phys.energyfloatArea[2.6e-07/0.0041] Flare area relative to stellar surface areaphys.areadoubleJ/ApJ/849/36/table1Parameters of flaring M dwarfsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKIC[892376/12835232] Kepler Input Catalog identifiermeta.id;meta.mainintprimaryDate[31.7/1415.3] Kepler observation timedtime.epochfloatFNum[8/1184] Number of flaresmeta.numberintPer[0.2/68.3]? Rotation perioddtime.periodfloatnullabler_PerReference for Per (1)meta.ref;pos.framecharAmp[200/85660] Amplitude of lightcurve from starspots (2)(10-6)src.var.amplitudeintHaH{alpha} line description (absorption, emission or "no data"=480 occurrences)meta.notecharHaLum[1.5e-05/0.00025]? Normalized H{alpha} activity luminosity (3)phys.luminosity;em.line.HalphadoublenullableFLum[3.2e-08/0.00034] Flare activity luminosity (3)phys.luminositydoublePCatDisplay data from McQuillan+ (2014, J/ApJS/211/24) and Reinhold+ (2013, J/A+A/560/A4)meta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPosition from KIC catalog (V/133) (right ascension part)degpos.eq.ra;meta.main_DEPosition from KIC catalog (V/133) (declination part)degpos.eq.dec;meta.main