J/A+A/668/A167ivo://CDS.VizieR/J/A+A/668/A167doi:10.26093/cds/vizier.36680167CDSVasilyev V.Reinhold T.Shapiro A.I.Krivova N.A.Usoskin I.,Montet B.T.Solanki S.K.Gizon L.2024-11-28T20:01:17Z2022-12-19T14:34:54ZCDS support team

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

cds-question@unistra.frstellar-flaresg-starsOver the past years, thousands of stellar flares have been detected by harvesting data from large photometric surveys. These detections, however, do not account for potential sources of contamination such as background stars appearing in the same aperture as the primary target. We present a new method for identifying the true flare sources in large photometric surveys using data from the Kepler mission. Potential flares are identified in two steps: first, we search the light curves for at least two subsequent data points exceeding a 5{\sigma} threshold above the running mean. For these two cadences, we subtract the "quiet" stellar flux from the Kepler pixel data to obtain new images where the potential flare is the main light source. In the second step, we use a Bayesian approach to fit the point spread function of the instrument to determine the most likely location of the flux excess on the detector. We applied our method to 5862 main-sequence stars with near-solar effective temperatures. We found 2274 events exceeding the 5-sigma in at least two consecutive points in the light curves. Applying the second step reduced this number to 342 superflares. Of these, 283 flares happened on 178 target stars, 47 events are associated with fainter background stars, and in 10 cases, the flare location cannot be distinguished between the target and a background star. We also present cases where flares have been reported previously but our technique could not attribute them to the target star. We conclude that 1) identifying outliers in the light curves alone is insufficient to attribute them to stellar flares and 2) flares can only be uniquely attributed to a certain star when the instrument pixel-level data together with the point spread function are taken into account. As a consequence, previous flare statistics are likely contaminated by instrumental effects and unresolved astrophysical sources.2022A&A...668A.167Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/668/A167CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/133 : Kepler Input Catalog (Kepler Mission Team, 2009)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/668/A167https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/668/A167http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/668/A167https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/668/A167https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/668/A167http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/668/A167GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/668/A167/table2 (The catalog of detected flares for 210 stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/668/A167/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/668/A167/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/668/A167/table2?GETtext/xml+votable180.050000true285.513416741.75466670.0055555555555555565/3646 3689-3690 3741 3743 3782 6/14579 14589-14591 14733-14735 14738 14744 14746 14752-14754 14765-14767 14769-14771 14774-14776 14778-14779 14781 14783 14792 14794 14818-14819 14824 14827 14830 14914 14919-14920 14922-14924 14929-14933 14935 14938-14940 14942-14943 14945-14948 14950-14951 14954-14956 14959 14961 14963 14968 14971 15041 15044 15059-15062 15105 15107 15109-15110 15112-15113 15118 15120-15121 15123-15124 15126-15127 15132-15134 15137 15139-15141 15143 15145-15150 15153 15155 15158-15160 15168-15170 15178https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/668/A167?format=asciidefaultJ/A+A/668/A167/table2The catalog of detected flares for 210 starsGaiaDR2Gaia DR2 ID of the target starmeta.idTimeTime when the flare startsdtime.epochdoubleSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintKICKepler KIC number of the target starmeta.id;meta.mainintdtDuration of the flaremintime.durationfloatEnergy? Flare energy1e-07Jphys.energydoublenullableProt? Rotation period of the target star measured by McQuillan et al. (2014ApJS..211...24M, Cat. J/ApJS/211/24)dtime.periodfloatnullableType[1/3] Classification flag for flare (1)meta.codeintGaiaDR2Bckg? GAIA DR2 ID of background stars for types 2 and 3meta.idnullable_RAPositions from Simbad and KIC (Cat. V/133) (right ascension part)degpos.eq.ra;meta.main_DEPositions from Simbad and KIC (Cat. V/133) (declination part)degpos.eq.dec;meta.main