J/A+A/686/A239ivo://CDS.VizieR/J/A+A/686/A239doi:10.26093/cds/vizier.36860239CDSBruno G.Pagano I.Scandariato G.Floren H.-G.Brandeker A.,Olofsson G.Maxted P.F.L.Fortier A.Sousa S.G.Sulis S.,Van Grootel V.Garai Z.Boldog A.Kriskovics L.Szabo M.Gy.,Gandolfi D.Alibert Y.Alonso R.Barczy T.Barrado Navascues D.,Barros S.C.Baumjohann W.Beck M.Beck T.Benz W.Billot N.,Borsato L.Broeg C.Collier Cameron A.Csizmadia Sz.Cubillos P.E.,Davies M.B.Deleuil M.Deline A.Delrez L.Demangeon O.D.S.,Demory B.-O.Ehrenreich D.Erikson A.Farinato J.Fossati L.,Fridlund M.Gillon M.Guedel M.Guenther M.N.Heitzmann A.Helling C.,Hoyer S.Isaak K.G.Kiss L.Lam K.W.F.Laskar J.,Lecavelier des Etangs A.Lendl M.Magrin D.Mordasini C.Nascimbeni V.,Ottensamer R.Palle E.Peter G.Piotto G.Pollacco D.Queloz D.,Ragazzoni R.Rando N.Ratti F.Rauer H.Ribas I.Santos N.C.,Sarajlic M.Segransan D.Simon A.E.Singh V.Smith A.M.S.Stalport M.,Thomas N.Udry S.Ulmer B.Venturini J.Villaver E.Walton N.A.,Wilson T.G.2024-11-21T20:01:05Z2024-06-18T08:37:33ZCDS support team

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

cds-question@unistra.frk-starsstellar-flaresphotometryvisible-astronomyWhite-light stellar flares are proxies for some of the most energetic types of flares, but their triggering mechanism is still poorly understood. As they are associated with strong X and UV emission, their study is particularly relevant to estimate the amount of high-energy irradiation onto the atmospheres of exoplanets, especially those in their stars' habitable zone. We used the high-cadence, high-photometric capabilities of the CHEOPS and TESS space telescopes to study the detailed morphology of white-light flares occurring in a sample of 130 late-K and M stars, and compared our findings with results obtained at lower cadence. We employed dedicated software for the reduction of 3s cadence CHEOPS data, and adopted the 20s cadence TESS data reduced by its official processing pipeline. We developed an algorithm to separate multi-peak flare profiles into their components, in order to contrast them to those of single-peak, classical flares. We also exploited this tool to estimate amplitudes and periodicities in a small sample of quasi-periodic pulsation (QPP) candidates. Complex flares represent a significant percentage (>~30%) of the detected outburst events. Our findings suggest that high-impulse flares are more frequent than suspected from lower-cadence data, so that the most impactful flux levels that hit close-in exoplanets might be more concentrated than expected. We found significant differences in the duration distributions of single and complex flare components, but not in their peak luminosity. A statistical analysis of the flare parameter distributions provides marginal support for their description with a log-normal instead of a power-law function, leaving the door open to several flare formation scenarios. We tentatively confirmed previous results about QPPs in high-cadence photometry, report the possible detection of a pre-flare dip, and did not find hints of photometric variability due to an undetected flare background. The high-cadence study of stellar hosts might be crucial to evaluate the impact of their flares on close-in exoplanets, as their impulsive phase emission might otherwise be incorrectly estimated. Future telescopes such as PLATO and Ariel, thanks to their high-cadence capability, will help on this aspect. As the details of flare profiles and of the shape of their parameter distributions are made more accessible by ever increasing instrument precision and time resolution, the models used to interpret them and their role in star-planet interactions might need to be updated constantly.2024A&A...686A.239Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/686/A239CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/686/A239https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/686/A239http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/686/A239https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/686/A239https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/686/A239http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/686/A239GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/686/A239/stars (List of studied stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/686/A239/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/686/A239/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/686/A239/stars?GETtext/xml+votable180.050000true48.0526232408800129.859004461420.0055555555555555566/131 307 546 870 1212 1845 1875 1896 1911 2737 2747 3031 3163 3715 4104 4444 5420 5488 5677 6346 6384 6552 6672 6883 7940 8440 8733 8739 9359 10303 10683 13512 13688 13743 13875 13912 16391 16758 18195 18496 18666 19064 19466 19668 20071 20100 20131 20311 20896 21171 21748 21953 22040 22309 22645 22807 23564 23735 23765 23793 24227 24713 25192 25528 25989 26555 26560 26583 26821 26972 27141 27201 27204 27289 27459 28223 28279 28343 28494 28548 28646 29684 30200 30429 30505 30625 30771 30833 30893 31014 31781 32052 32089 32115 32319 32335 32491 36078 36174 36526 37942 38551 40513 41591 42101 42290 42652 44379 44921 46598 46632 48263 48274 49101https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/686/A239?format=asciiOpticaldefaultJ/A+A/686/A239/starsList of studied starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainNameStar namemeta.id;meta.maincharLC1Show the light curvemeta.ref.urlcharFileName1Name fo the light curve file in subdirectory lcmeta.id;meta.filecharLC2Show the light curvemeta.ref.urlcharFileName2Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC3Show the light curvemeta.ref.urlcharFileName3Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC4Show the light curvemeta.ref.urlcharFileName4Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC5Show the light curvemeta.ref.urlcharLC6Show the light curvemeta.ref.urlcharFileName5Name of other light curve file in subdirectory lc for AU Micmeta.idcharFileName6Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC7Show the light curvemeta.ref.urlcharFileName7Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC8Show the light curvemeta.ref.urlcharFileName8Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC9Show the light curvemeta.ref.urlcharFileName9Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC10Show the light curvemeta.ref.urlcharFileName10Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC11Show the light curvemeta.ref.urlcharFileName11Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC12Show the light curvemeta.ref.urlcharFileName12Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC13Show the light curvemeta.ref.urlcharFileName13Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC14Show the light curvemeta.ref.urlcharFileName14Name of other light curve file in subdirectory lc for AU Micmeta.idcharLC15Show the light curvemeta.ref.urlcharFileName15Name of other light curve file in subdirectory lc for AU Micmeta.idchar