J/MNRAS/463/1844ivo://CDS.VizieR/J/MNRAS/463/1844doi:10.26093/cds/vizier.74631844CDSStelzer B.Damasso M.Scholz A.Matt S.P.2024-08-16T20:19:03Z2018-07-03T13:08:51ZCDS support team

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

cds-question@unistra.frm-starslate-type-starsphotometrystellar-massesstellar-distanceeffective-temperatureWe study the relation between stellar rotation and magnetic activity for a sample of 134 bright, nearby M dwarfs observed in the Kepler Two-Wheel (K2) mission during campaigns C0 to C4. The K2 lightcurves yield photometrically derived rotation periods for 97 stars (79 of which without previous period measurement), as well as various measures for activity related to cool spots and flares. We find a clear difference between fast and slow rotators with a dividing line at a period of ~10d at which the activity level changes abruptly. All photometric diagnostics of activity (spot cycle amplitude, flare peak amplitude and residual variability after subtraction of spot and flare variations) display the same dichotomy, pointing to a quick transition between a high-activity mode for fast rotators and a low-activity mode for slow rotators. This unexplained behavior is reminiscent of a dynamo mode-change seen in numerical simulations that separates a dipolar from a multipolar regime. A substantial number of the fast rotators are visual binaries. A tentative explanation is accelerated disk evolution in binaries leading to higher initial rotation rates on the main-sequence and associated longer spin-down and activity lifetimes. We combine the K2 rotation periods with archival X-ray and UV data. X-ray, FUV and NUV detections are found for 26, 41, and 11 stars from our sample, respectively. Separating the fast from the slow rotators, we determine for the first time the X-ray saturation level separately for early- and for mid-M stars.2016MNRAS.463.1844Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/463/1844CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/142/138 : All-sky catalog of bright M dwarfs (Lepine+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/463/1844https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/463/1844http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/463/1844https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/463/1844https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/463/1844http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/463/1844GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/463/1844/table1 (Target list for K2 Campaign C0-C4 with stellar parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/463/1844/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/463/1844/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/463/1844/table1?GETtext/xml+votable180.050000true92.57422.57220.0055555555555555566/260 270 280 285 295 301 304-305 307 310 323 330 337 339-340 358 378 381 409 465 469-470 477 1058 17087 18439 18462 18482 18496 18498 18538 18569 18584 18588 18609 18617 18624 18634 18648 18657 18659 23482 23487 23523 23526 23532 23534 23548 23857-23858 23911 23939 23945 23960 23968 23974 24002 24004 24040 24058 24062 24327 24336 24343 24385 24391 24394 25595 26946 26956 26969 26971-26972 26977 26983 26990 26996 27000 27004 27007 27029 27091 27663 27681 27683 27692 27694 27706 27784 27787 27792 29327 29344 29348 29352 29354 29362 30723 30729-30731 42903 42910 42933 42939 42950 42953 42967 42982 42985-42986 43001 44308 44371 44375 44378 485007.952274030004205e-20 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/463/1844?format=asciidefaultJ/MNRAS/463/1844/table1Target list for K2 Campaign C0-C4 with stellar parameterse_Vmagrms uncertainty on Vmagmagstat.error;phot.magfloatJmagJ magnitudemagphot.mag;em.IR.Jfloate_Jmagrms uncertainty on Jmagmagstat.error;phot.magfloatKsmagKs magnitudemagphot.mag;em.IR.Kfloate_Ksmagrms uncertainty on Ksmagmagstat.error;phot.magfloatDistDistancepcpos.distance;pos.heliocentricfloatSimbadSimbad column added by the CDSmeta.ref.urlcharMassStellar masssolMassphys.massfloate_Massrms uncertainty on stellar masssolMassstat.error;phys.massfloatRadStellar radiussolRadphys.size.radiusfloate_Radrms uncertainty on Stellar radiussolRadstat.errorfloatlogLbolBolometric luminositylog(solLum)phys.luminosityfloate_logLbolrms uncertainty on bolometric luminositylog(solLum)stat.errorfloatTeffEffective temperatureKphys.temperature.effectiveinte_Teffrms uncertainty on TeffKstat.error;phys.temperature.effectiveintSpTypeSpectral typesrc.spTypecharEPICcatDisplay the K2 EPIC data (Huber et al., 2007, Cat. IV/34)meta.ref.urlcharPMDisplay the data of Lepine & Gaidos (2011, Cat. J/AJ/142/138)meta.ref.urlchar_RAPositions from EPIC catalog (Cat. IV/34) (right ascension part)degpos.eq.ra;meta.main_DEPositions from EPIC catalog (Cat. IV/34) (declination part)degpos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEPICEPIC identification numbermeta.id;meta.mainlongn_EPIC[*Ba ] Note on EPIC (1)meta.notecharCampaignCampaign (C0-C4)meta.id;obscharCNS-nameCNS name (Gliese & Jahreiss, 1991, Cat. V/70)meta.idcharKpmagKepler magnitudemagphot.mag;em.optfloatVmagV magnitudemagphot.mag;em.opt.VfloatJ/MNRAS/463/1844/table2Rotation and activity parameters derived from the K2 light curves (all target but 206262223)RperRper parameter (3)%stat.fit.paramfloatFlag[YN?] Flag (1)meta.code.errorcharR0? Rossby number (2)stat.paramfloatnullableSphSph parameter (3)(10-6)stat.fit.paramfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEPICEPIC identification numbermeta.id;meta.mainlongProt? Rotational perioddtime.periodfloatnullableMethodMethod usedmeta.notechar