J/MNRAS/407/2269ivo://CDS.VizieR/J/MNRAS/407/2269doi:10.26093/cds/vizier.74072269CDSMorin J.Donati J.-F.Petit P.Delfosse X.Forveille T.Jardine M.M.2024-07-12T20:14:33Z2010-09-21T08:06:39ZCDS support team

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

cds-question@unistra.frm-starsdwarf-starsmagnetic-fieldsWe present here the final results of the first spectropolarimetric survey of a small sample of active M dwarfs, aimed at providing observational constraints on dynamo action on both sides of the full-convection threshold (spectral type M4). Our two previous studies (Donati et al. 2008. Cat. J/MNRAS/390/545; Morin et al., 2008, Cat. J/MNRAS/384/77) were focused on early and mid M dwarfs. The present paper examines 11 fully convective late M dwarfs (spectral types M5-M8). Tomographic imaging techniques were applied to time-series of circularly polarised profiles of 6 stars, in order to infer their large-scale magnetic topologies. For 3 other stars we could not produce such magnetic maps, because of low variability of the Stokes V signatures, but were able to derive some properties of the magnetic fields. We find 2 distinct categories of magnetic topologies: on the one hand strong axisymmetric dipolar fields (similar to mid M dwarfs), and on the other hand weak fields generally featuring a significant non-axisymmetric component, and sometimes a significant toroidal one. Comparison with unsigned magnetic fluxes demonstrates that the second category of magnetic fields shows less organization (less energy in the large scales), similarly to partly convective early M dwarfs. Stars in both categories have similar stellar parameters, our data do not evidence a separation between these 2 categories in the mass-rotation plane. We also report marginal detection of a large-scale magnetic field on the M8 star VB 10 featuring a significant toroidal axisymmetric component, whereas no field is detectable on VB 8 (M7).2010MNRAS.407.2269Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/407/2269CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/cfht : Log of CFHT Exposures (CADC, 1979-)I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)III/198 : Palomar/MSU nearby star spectroscopic survey (Hawley+ 1997)J/A+A/331/581 : Rotation and activity in field M dwarfs (Delfosse+ 1998)J/MNRAS/390/545 : Magnetic topologies of early M dwarfs (Donati+, 2008)J/MNRAS/390/567 : Magnetic topologies of mid M dwarfs (Morin+, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/407/2269https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/407/2269http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/407/2269https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/407/2269https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/407/2269http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/407/2269GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/407/2269/stars (Stars positions and fundamental parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/407/2269/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/407/2269/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/407/2269/stars?GETtext/xml+votable180.050000true15.832166762.36547220.0055555555555555566/3715 5000 5534 14772 26279 26699 27462 27762 29458 30505 30833https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/407/2269?format=asciidefaultJ/MNRAS/407/2269/starsStars positions and fundamental parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameDesignation of the starmeta.id;phys.atmol.configuration;meta.maincharprimaryRAJ2000Simbad Hour of Right Ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Simbad Degree of Declination (J2000.0)pos.eq.dec;meta.mainGJGliese-Jahreiss designationsmeta.idcharFileNumber of the corresponding table in the papermeta.numbercharZDI[yes no] Zeeman Doppler Imaging was conductedmeta.codecharSpTMK spectral type (1)src.spTypecharMassMass of the star (2)solMassphys.massfloatl_e_MassLimit flag on e_Mass (2)meta.code.errorchare_MassFormal 1-sigma error bar on Mass (2)solMassstat.error;phys.massfloatl_vsiniLimit flag on vsini (3)meta.code.error;phys.veloc.rotatcharvsiniEquatorial rotational velocity along line of sight (3)km/sphys.veloc.rotatintr_vsini? Reference for vsini (3)meta.refcharl_BfLimit flag on Bf (4)meta.code.errorcharBf? Magnetic flux (4)0.1Tphot.fluxfloatnullabler_Bf[a-c] Reference for Bf (5)meta.ref;pos.framecharl_ProtLimit flag for Prot (6)meta.code.errorcharProtRotation period (6)dtime.periodfloate_Prot? 3-sigma error bar on Prot (6)dstat.errorfloatnullabletaucEmpirical convective turnover time (7)dtime.intervalintl_RoLimit flag on empirical Rossby number (7)meta.code.errorcharRoEmpirical Rossby number (7)stat.paramfloatRsini? Stellar radius times sini (8)solRadphys.size.radiusfloatnullablel_e_RsiniLimit flag on error on Rsini (8)meta.code.errorchare_Rsini? Formal 1-sigma error bar on Rsini (8)solRadstat.errorfloatnullableRadTheoretical stellar radius (9)solRadphys.size.radiusfloatl_e_RadLimit flag on error on Rad (9)meta.code.errorchare_RadFormal 1-sigma error bar on Rad (9)solRadstat.errorfloatincl? Inclination of the stellar rotation axis (10)degsrc.orbital.inclinationintnullableSimbadSimbad column added by the CDScharJ/MNRAS/407/2269/tablesDates, magnetic field and radial velocity (tables A1-A11 of the paper)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameDesignation of the starmeta.id;phys.atmol.configurationcharDateUT datetime.epochnullableHJDUT heliocentric Julian datedtime.epochdoubleS/NSignal to noise ratiostat.snrintrmsrms noise of circular polarisation in units of 10^-4^Ic (Ic=unpolarised continuum) (4)stat.stdev;phys.polarization.circularfloatBlLongitudinal magnetic field (Gauss) (1)0.0001Tphys.magFieldinte_Blrms uncertainty on Bl (1)0.0001Tstat.errorintRVRadial velocity (2)km/sphys.veloc;pos.heliocentricfloatE? Rotation cycle (3)time.phasedoublenullableHJD0? Reference HJD for E (3)meta.ref;time.epochdoublenullable