J/A+A/702/A111ivo://CDS.VizieR/J/A+A/702/A111doi:10.26093/cds/vizier/bc-ny/lbbbCDSCristofari P.I.Donati J.-F.Bellotti S.Artigau E.Carmona A.,Moutou C.Delfosse X.Petit P.Finociety B.Dias do Nascimento J.2026-08-03T06:57:40Z2025-10-13T10:19:42ZCDS support team

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

cds-question@unistra.frm-starsmagnetic-fieldsM dwarfs are known to host magnetic fields, impacting exoplanet studies and playing a key role in stellar and planetary formation and evolution. Observations revealed the long-term evolution of the large-scale magnetic field reconstructed with Zeeman-Doppler imaging, and a diversity of their topologies. These large-scale magnetic fields only account for a small amount of the unsigned magnetic flux that can be probed by directly modeling the Zeeman broadening of spectral lines in unpolarized spectra. We aim at investigating the long-term behavior of the average small-scale magnetic field of M dwarfs with time, and assess our ability to detect rotational modulation from time series of field measurements derived from unpolarized spectra. We perform fits of synthetic spectra computed with ZeeTurbo to near-infrared high-resolution spectra recorded with SPIRou between 2019 and 2024 in the context of the SLS and SPICE large programs. The analysis is performed on the spectra of 2 partially convective (AD Leo, DS Leo) and 3 fully convective (PM J18482+0741, CN Leo, Barnard star) M dwarfs, along with EV Lac whose mass is close to the fully-convective limit. Our analysis provides measurements of the average small-scale magnetic field, which are compared to longitudinal magnetic field and temperature variation measurements (dTemp) obtained from the same data. We were able to detect the rotation period in the small-scale magnetic field series for 4 of the 6 stars in our sample. We find that the average magnetic field can vary by up to 0.3kG throughout the year (e.g., CN Leo), or of up to 1kG across rotation phases. The rotation periods retrieved from longitudinal and small-scale magnetic fields are found in agreement within error bars. dTemp measurements are found to anti-correlate with small- scale magnetic field measurements for three stars (EV Lac, DS Leo and Barnard's star). The results demonstrate our ability to measure rotation periods from high-resolution data through small-scale magnetic field measurements, provided that the inclination of the observed targets is sufficiently large. We observe long-term fluctuations of the average magnetic field that could indicate magnetic cycles in the parent dynamo processes. These long-term variations appear mainly uncorrelated with large-scale magnetic field variations probed through longitudinal field measurements. Large variations in the amplitude of the rotationally modulated signals, in particular, hint towards a change in the distribution of the surface inhomogeneities accessible to Zeeman broadening measurements.2025A&A...702A.111Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/702/A111CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/702/A111https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/702/A111http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/702/A111https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/702/A111https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/702/A111http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/702/A111GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/702/A111/table2 (Atmospheric parameters and small-scale magnetic field)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/702/A111/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/702/A111/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/702/A111/table2?GETtext/xml+votable180.050000true165.659758321.96713890.0055555555555555566/4444 13743 27462 28341 30455 31781https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/702/A111?format=asciidefaultJ/A+A/702/A111/table2Atmospheric parameters and small-scale magnetic fieldrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharTeffEffective temperatureKphys.temperature.effectiveinte_TeffEffective temperature errorKstat.error;phys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloate_loggSurface gravity errorlog(cm.s**-2)stat.errorfloat[M/H]Metallicityphys.abund.Zfloate_[M/H]Metallicity errorstat.error;phys.abundfloatn_[M/H][c] Notre on [M/H] (1)meta.notecharl_vsiniLimit flag on vsinimeta.code.error;phys.veloc.rotatcharvsiniProjected rotational velocity (2)km/sphys.veloc.rotatfloatn_vsini[d] Note on vsini (1)meta.notecharIncl? Inclination (3)degsrc.orbital.inclinationintnullablee_Incl? Inclination errordegstat.errorintnullableksiRTMicro-turbulent velocity (4)km/sphys.veloc.microTurbfloate_ksiRTMicro-turbulent velocity errorkm/sstat.errorfloatSimbadSimbad column added by the CDSmeta.ref.urlchar<B>Surface magnetic fieldkGphys.magFieldfloate_<B>Surface magnetic field errorkGstat.errorfloatplot<B>Show the <B> curvesmeta.ref.urlcharFileName1Name of the table with <B> and dTemp measurementsmeta.id;meta.datasetcharplotBlShow the Bl curvesmeta.ref.urlcharFileName2Name of the table with Bl measurementsmeta.id;meta.datasetchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/A+A/702/A111/tablea7<B> and dTemp Measurements obtained each night for DS Leoe_f0Uncertainty on f0stat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datetime.epochdouble<B>Surface magnetic fieldkGphys.magFieldfloate_<B>Uncertainty on surface magnetic fieldkGstat.errorfloatf00kG component filling factorarith.factor;stat.fillingfloatf22kG component filling factorarith.factor;stat.fillingfloate_f2Uncertainty on f2stat.errorfloatf44kG component filling factorarith.factor;stat.fillingfloate_f4Uncertainty on f4stat.errorfloatf66kG component filling factorarith.factor;stat.fillingfloate_f6Uncertainty on f6stat.errorfloatf88kG component filling factorarith.factor;stat.fillingfloate_f8Uncertainty on f8stat.errorfloatf1010kG component filling factorarith.factor;stat.fillingfloate_f10Uncertainty on f10stat.errorfloatdTemp? Temperature variation estimatesKphys.temperaturefloatnullablee_dTemp? Uncertainty on dTempKstat.errorfloatnullableJ/A+A/702/A111/tablea8<B> and dTemp Measurements obtained each night for EV LacrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datetime.epochdouble<B>Surface magnetic fieldkGphys.magFieldfloate_<B>Uncertainty on surface magnetic fieldkGstat.errorfloatf00kG component filling factorarith.factor;stat.fillingfloate_f0Uncertainty on f0stat.errorfloatf22kG component filling factorarith.factor;stat.fillingfloate_f2Uncertainty on f2stat.errorfloatf44kG component filling factorarith.factor;stat.fillingfloate_f4Uncertainty on f4stat.errorfloatf66kG component filling factorarith.factor;stat.fillingfloate_f6Uncertainty on f6stat.errorfloatf88kG component filling factorarith.factor;stat.fillingfloate_f8Uncertainty on f8stat.errorfloatf1010kG component filling factorarith.factor;stat.fillingfloate_f10Uncertainty on f10stat.errorfloatdTemp? Temperature variation estimatesKphys.temperaturefloatnullablee_dTemp? Uncertainty on dTempKstat.errorfloatnullableJ/A+A/702/A111/tablea9<B> and dTemp Measurements obtained each night for AD LeorecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datetime.epochdouble<B>Surface magnetic fieldkGphys.magFieldfloate_<B>Uncertainty on surface magnetic fieldkGstat.errorfloatf00kG component filling factorarith.factor;stat.fillingfloate_f0Uncertainty on f0stat.errorfloatf22kG component filling factorarith.factor;stat.fillingfloate_f2Uncertainty on f2stat.errorfloatf44kG component filling factorarith.factor;stat.fillingfloate_f4Uncertainty on f4stat.errorfloatf66kG component filling factorarith.factor;stat.fillingfloate_f6Uncertainty on f6stat.errorfloatf88kG component filling factorarith.factor;stat.fillingfloate_f8Uncertainty on f8stat.errorfloatf1010kG component filling factorarith.factor;stat.fillingfloate_f10Uncertainty on f10stat.errorfloatdTemp? Temperature variation estimatesKphys.temperaturefloatnullablee_dTemp? Uncertainty on dTempKstat.errorfloatnullableJ/A+A/702/A111/tablea10<B> and dTemp Measurements obtained each night for CN LeorecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datetime.epochdouble<B>Surface magnetic fieldkGphys.magFieldfloate_<B>Uncertainty on surface magnetic fieldkGstat.errorfloatf00kG component filling factorarith.factor;stat.fillingfloate_f0Uncertainty on f0stat.errorfloatf22kG component filling factorarith.factor;stat.fillingfloate_f2Uncertainty on f2stat.errorfloatf44kG component filling factorarith.factor;stat.fillingfloate_f4Uncertainty on f4stat.errorfloatf66kG component filling factorarith.factor;stat.fillingfloate_f6Uncertainty on f6stat.errorfloatf88kG component filling factorarith.factor;stat.fillingfloate_f8Uncertainty on f8stat.errorfloatf1010kG component filling factorarith.factor;stat.fillingfloate_f10Uncertainty on f10stat.errorfloatdTemp? Temperature variation estimatesKphys.temperaturefloatnullablee_dTemp? Uncertainty on dTempKstat.errorfloatnullableJ/A+A/702/A111/tablea11<B> and dTemp Measurements obtained each night for PMJ 18482+074recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datetime.epochdouble<B>Surface magnetic fieldkGphys.magFieldfloate_<B>Uncertainty on surface magnetic fieldkGstat.errorfloatf00kG component filling factorarith.factor;stat.fillingfloate_f0Uncertainty on f0stat.errorfloatf22kG component filling factorarith.factor;stat.fillingfloate_f2Uncertainty on f2stat.errorfloatf44kG component filling factorarith.factor;stat.fillingfloate_f4Uncertainty on f4stat.errorfloatf66kG component filling factorarith.factor;stat.fillingfloate_f6Uncertainty on f6stat.errorfloatf88kG component filling factorarith.factor;stat.fillingfloate_f8Uncertainty on f8stat.errorfloatf1010kG component filling factorarith.factor;stat.fillingfloate_f10Uncertainty on f10stat.errorfloatdTemp? Temperature variation estimatesKphys.temperaturefloatnullablee_dTemp? Uncertainty on dTempKstat.errorfloatnullableJ/A+A/702/A111/tablea12<B> and dTemp Measurements obtained each night for Barnard's starrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datetime.epochdouble<B>Surface magnetic fieldkGphys.magFieldfloate_<B>Uncertainty on surface magnetic fieldkGstat.errorfloatf00kG component filling factorarith.factor;stat.fillingfloate_f0Uncertainty on f0stat.errorfloatf22kG component filling factorarith.factor;stat.fillingfloate_f2Uncertainty on f2stat.errorfloatf44kG component filling factorarith.factor;stat.fillingfloate_f4Uncertainty on f4stat.errorfloatf66kG component filling factorarith.factor;stat.fillingfloate_f6Uncertainty on f6stat.errorfloatf88kG component filling factorarith.factor;stat.fillingfloate_f8Uncertainty on f8stat.errorfloatf1010kG component filling factorarith.factor;stat.fillingfloate_f10Uncertainty on f10stat.errorfloatdTemp? Temperature variation estimatesKphys.temperaturefloatnullablee_dTemp? Uncertainty on dTempKstat.errorfloatnullableJ/A+A/702/A111/tablea13Bl measurements obtained each night for DS LeorecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datedtime.epochdoubleBlLongitudinal magnetic fieldGphys.magFieldfloate_BlUncertainty on longitudinal magnetic fieldGstat.errorfloatJ/A+A/702/A111/tablea14Bl measurements obtained each night for EV LacrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datedtime.epochdoubleBlLongitudinal magnetic fieldGphys.magFieldfloate_BlUncertainty on longitudinal magnetic fieldGstat.errorfloatJ/A+A/702/A111/tablea15Bl measurements obtained each night for AD LeorecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datedtime.epochdoubleBlLongitudinal magnetic fieldGphys.magFieldfloate_BlUncertainty on longitudinal magnetic fieldGstat.errorfloatJ/A+A/702/A111/tablea16Bl measurements obtained each night for CN LeorecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datedtime.epochdoubleBlLongitudinal magnetic fieldGphys.magFieldfloate_BlUncertainty on longitudinal magnetic fieldGstat.errorfloatJ/A+A/702/A111/tablea17Bl measurements obtained each night for PMJ 18482+0741MJDModified Julian Datedtime.epochdoubleBlLongitudinal magnetic fieldGphys.magFieldfloate_BlUncertainty on longitudinal magnetic fieldGstat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ/A+A/702/A111/tablea18Bl measurements obtained each night for Barnard's starrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDModified Julian Datedtime.epochdoubleBlLongitudinal magnetic fieldGphys.magFieldfloate_BlUncertainty on longitudinal magnetic fieldGstat.errorfloat