J/ApJ/909/106ivo://CDS.VizieR/J/ApJ/909/106doi:10.26093/cds/vizier.19090106CDSXin L.P.Li H.L.Wang J.Han X.H.Xu Y.Meng X.M.Cai H.B.Huang L.,Lu X.M.Qiu Y.L.Wang X.G.Liang E.W.Dai Z.G.Wang X.Y.Wu C.,Zhang J.B.Li G.W.Turpin D.Feng Q.C.Deng J.S.Sun S.S.Zheng T.C.,Yang Y.G.Wei J.Y.2024-11-06T20:23:11Z2024-04-05T09:06:29ZCDS support team

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

cds-question@unistra.frstellar-flaresinfrared-photometryvisible-astronomyphotometryspectroscopym-starsWe report the detection and follow-up of a superstellar flare GWAC181229A with an amplitude of {Delta}R~9.5mag on an M9-type star by SVOM/GWAC and the dedicated follow-up telescopes. The estimated bolometric energy Ebol is (5.56-9.25)x10^34^erg, which makes the event one of the most powerful flares seen on ultracool stars. The magnetic strength is inferred to be 3.6-4.7kG. Thanks to sampling with a cadence of 15s, a new component near the peak time with a very steep decay is detected in the R-band light curve, followed by the two-component flare template given by Davenport+ (2014ApJ...797..122D). An effective temperature of 5340+/-40K is measured by fitting a blackbody shape to the spectrum in the shallower phase during the flare. The filling factors of the flare are estimated to be ~30% and 19% at the peak time and at 54 minutes after the first detection. The detection of this particular event with large amplitude, huge emitted energy, and a new component demonstrates that high-cadence sky monitoring cooperation with fast follow-up observations is very important for understanding the violent magnetic activity.2021ApJ...909..106Xhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/909/106CatalogResearchIsServedByTAP VizieR generic servicerelated-toV/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/A+A/333/231 : O-M stars model atmospheres (Bessell+ 1998)J/A+A/487/293 : Em. lines in a giant flare of CN Leo (Fuhrmeister+, 2008)J/AJ/141/97 : SDSS DR7 M dwarfs (West+, 2011)J/MNRAS/435/2161 : Catalogue of bright (K<9) M dwarfs (Frith+, 2013)J/ApJS/207/15 : M dwarf flare spectra (Kowalski+, 2013)J/ApJ/794/120 : Sloan Digital Sky Survey coadd. Stripe 82 (Annis+, 2014)J/AJ/149/158 : The BUD sample. I. L dwarf activity sample (Schmidt+, 2015)J/ApJ/829/23 : Stellar flares from Q0-Q17 Kepler LCs (Davenport, 2016)J/ApJ/858/55 : K2 ultracool dwarfs survey. III. Flares (Paudel+, 2018)J/A+A/623/A127 : Homogeneous sample of 34000 M7-M9.5 dwarfs (Ahmed+, 2019)J/ApJ/876/115 : Optical follow-up of ASAS-SN M dwarf flares (Schmidt+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/909/106https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/909/106http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/909/106https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/909/106https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/909/106http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/909/106GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap2.762881831355591e-19 3.3785437584409506e-19OpticalInfrareddefaultJ/ApJ/909/106/fig2R-band light curve of GWAC181229ArecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJDJulian Date of the observationdtime.epochdoubleExp[10/150] Exposure timestime.duration;obs.exposureintRmag[13.49/19.1] Apparent R band magnitudemagphot.mag;em.opt.Rfloate_Rmag[0.03/0.6] Uncertainty in Rmagmagstat.error;phot.magfloatTelTelescope code (1)meta.code;instr.telcharJ/ApJ/909/106/fig6The spectrum obtained by the 2.16m telescope at Xinglong observatory, ChinarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[3731.84/8691.75] Wavelength; Angstroms0.1nmem.wldoubleFlux[-3.42e-16/1.6e-15] Flux; in erg/s/cm^2^/Angstrom unitscW.m**-2.nm**-1meta.unitdouble