J/ApJ/814/35ivo://CDS.VizieR/J/ApJ/814/35doi:10.26093/cds/vizier.18140035CDSChang S.-W.Byun Y.-I.Hartman J.D.2018-07-19T07:34:38Z2016-03-22T14:53:17ZCDS support team

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

cds-question@unistra.frvariable-starsstellar-flaresopen-star-clustersinfrared-photometryvisible-astronomyphotometryBased on one-month long MMT time-series observations of the open cluster M37, we monitored light variations of nearly 2500 red dwarfs and successfully identified 420 flare events from 312 cluster M dwarf stars. For each flare light curve, we derived observational and physical parameters, such as flare shape, peak amplitude, duration, energy, and peak luminosity. We show that cool stars produce serendipitous flares energetic enough to be observed in the r-band, and their temporal and peak characteristics are almost the same as those in traditional U-band observations. We also found many large-amplitude flares with inferred {Delta}u>6mag in the cluster sample which had been rarely reported in previous ground-based observations. Following the ergodic hypothesis, we investigate in detail statistical properties of flare parameters over a range of energy (E_r_~=10^31^-10^34^erg). As expected, there are no statistical differences in the distributions of flare timescales, energies, and frequencies among stars of the same age and mass group. We note that our sample tend to have longer rise and decay timescales compared to those seen in field flare stars of the same spectral type and be more energetic. Flare frequency distributions follow power-law distributions with slopes {beta}~0.62-1.21 for all flare stars and {beta}~0.52-0.97 for stars with membership information (P_mem_>=0.2). These are in general agreement with previous works on flare statistics of young open clusters and nearby field stars. Our results give further support to the classical age-activity relations.2015ApJ...814...35Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/814/35CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/ocl : Optically visible open clusters and Candidates (Dias+ 2002-2015)II/131 : Tonantzintla Pleiades Flare Stars (Haro+ 1982)J/ApJ/809/161 : X-ray obs. and membership probabilities of M37 (Nunez+, 2015)J/AJ/150/27 : New catalog of variable stars in M37 field (Chang+, 2015)J/ApJS/209/5 : Superflares of Kepler stars. I. (Shibayama+, 2013)J/ApJS/207/15 : M dwarf flare spectra (Kowalski+, 2013)J/ApJ/754/4 : HST monitoring of flaring stars in the bulge (Osten+, 2012)J/other/Nat/485.478 : Superflares on solar-type stars (Maehara+, 2012)J/AJ/141/97 : SDSS DR7 M dwarfs (West+, 2011)J/AJ/141/50 : White-light flares on cool Kepler stars (Walkowicz+, 2011)J/AJ/140/1402 : M dwarf flares from SDSS spectra (Hilton+, 2010)J/AJ/140/483 : Flares of UV Cet type stars (Dal+, 2010)J/ApJ/675/1233 : gri photometry in M37 (NGC 2099) (Hartman+, 2008)J/AJ/135/785 : SDSS-DR5 low-mass star spectroscopic sample (West+, 2008)J/AJ/134/2398 : Stellar SEDs in SDSS and 2MASS filters (Covey+, 2007)J/ApJ/606/466 : X-ray variability in NGC 2516 (Wolk+, 2004)J/A+A/327/1114 : Optical flares on EV Lac in 1967-1977 (Leto+ 1997)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/814/35https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/814/35http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/814/35https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/814/35https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/814/35http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/814/35GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/814/35/stars (List of flare stars; table added by CDS)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/814/35/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/814/35/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/814/35/stars?GETtext/xml+votable180.050000true87.83529166732.3668750.0055555555555555566/24520 24522https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/814/35?format=asciiInfraredOpticaldefaultJ/ApJ/814/35/starsList of flare stars; table added by CDSrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVarIDVariable star ID (among V42 to V2306) (G1)meta.id;meta.maincharprimaryMmLink to flare events data detected in the cluster sample (table 7)meta.ref.urlcharrmag[16.7/24.5] r band magnitudemagphot.mag;em.opt.RfloatH08Display Hartman+, 2008, J/ApJ/675/1233, data within 0.4"meta.ref.urlintnullableNfNumber of flare event for this starmeta.numberintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from Chang+, 2015, J/AJ/150/27 (right ascension part)degpos.eq.ra;meta.main_DEPositions from Chang+, 2015, J/AJ/150/27 (declination part)degpos.eq.dec;meta.mainJ/ApJ/814/35/table6Observational parameters of 604 flare events detected in the whole samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVarIDVariable star ID (among V42 to V2306) (G1)meta.id;meta.maincharrmag[16.7/24.5] r band magnitudemagphot.mag;em.opt.RfloatFlIDFlare event ID (F1-F6) (2)meta.id.assocchartpeak? Modified Julian Date at flare peakdtime.epochdoublenullablempeak[0.01/3.8]? The incremental magnitude at flare peakmagphot.magfloatnullablembase[0/1.1]? The magnitude difference (3)magphot.mag;arith.difffloatnullablet0.9r? The flare timescale; q=0.9, rise partmintime.scalefloatnullablet0.9d? The flare timescale; q=0.9, decay partmintime.scalefloatnullablet0.5r? The flare timescale; q=0.5, rise partmintime.scalefloatnullablet0.5d? The flare timescale; q=0.5, decay partmintime.scalefloatnullablet0.2r? The flare timescale; q=0.2, rise partmintime.scalefloatnullablet0.2d? The flare timescale; q=0.2, decay partmintime.scalefloatnullablet0.0r? The flare timescale; q=0, rise partmintime.scalefloatnullablet0.0d? The flare timescale; q=0, decay partmintime.scalefloatnullableJ/ApJ/814/35/table7Physical parameters of 420 flare events detected in the cluster sampleFlIDFlare event ID (F1-F5)meta.id.assoccharl_Tau0Limit flag on Tau0meta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVarIDVariable star ID (among V78 to V2306) (G1)meta.id;meta.maincharrmag[18/24.5] r band magnitudemagphot.mag;em.opt.RfloatTau0[3.5/508] Flare durationmintime.durationfloatl_PrLimit flag on Prmeta.code.errorcharPr[2/13416] The equivalent durationstime.durationintlogLr[29.5/32.1]? The quiescent luminosity of the starlog(1e-07W)phys.luminosityfloatnullablel_logLrpkLimit flag on logLrpkmeta.code.errorcharlogLrpk[28.9/31.9] The flare luminosity at maximum brightnesslog(1e-07W)phys.luminosityfloatl_logErLimit flag on logErmeta.code.errorcharlogEr[31.4/35.3] The Flare energylog(1e-07J)phys.energyfloatPmem? Cluster membership probability from Nunez et al. (2015, J/ApJ/809/161)%statfloatnullable