Magnetic fields and differential rotation on the pre‐main sequence – II. The early‐G star HD 141943 – coronal magnetic field, Hα emission and differential rotation
Identifieur interne : 006394 ( Main/Exploration ); précédent : 006393; suivant : 006395Magnetic fields and differential rotation on the pre‐main sequence – II. The early‐G star HD 141943 – coronal magnetic field, Hα emission and differential rotation
Auteurs : S. C. Marsden [Australie] ; M. M. Jardine [Australie] ; J. C. Ramírez Vélez [France, Australie] ; E. Alecian [France, Australie] ; C. J. Brown [Australie] ; B. D. Carter [Australie] ; J. Donati [France, Australie] ; N. Dunstone [Australie] ; R. Hart [Australie] ; M. Semel [France, Australie] ; I. A. Waite [Australie]Source :
- Monthly Notices of the Royal Astronomical Society [ 0035-8711 ] ; 2011-05-21.
Descripteurs français
- Pascal (Inist)
- Activité stellaire, Brillance surface, Champ azimutal, Champ magnétique, Champ radial, Dipôle, Distribution brillance, Déconvolution, Emission champ, Etoile G, Etoile K, Etoile S, Etoile jeune, Harmonique sphérique, Observation spectroscopique, Profil raie, Raie H alpha, Rapport signal bruit, Rotation différentielle, Spectropolarimétrie, Tache stellaire, Topologie, Type spectral.
English descriptors
- KwdEn :
- Absolute value, Active longitudes, Active stars, April, Average spottedness, Axisymmetric, Azimuthal, Azimuthal field, Brightness distribution, Brightness features, Brightness image, Brightness images, Cameron, Collier, Collier cameron, Convective, Convective zone, Convective zone depth, Corona, Coronal, Cutispoto, Data sets, Deconvolution, Differential, Differential rotation, Differential rotation measurements, Differential rotation measures, Diger, Dipole component, Dipoles, Donati, Donati collier cameron, Donati landstreet, Donati rees, Donati semel, Doppler, Doppler imaging method, Dynamo, Eld, Ellipse, Emission measure, Epoch, Equatorial rotation period, Error ellipses, Field emission, Fractional spottedness, Fresnel rhomb, G stars, Granzer, H-alpha lines, High levels, Higher levels, Hillenbrand, Imaging, Imaging code, Inclination angle, Interface layer, Jeffers, Jeffers donati, K stars, Latitude, Line shape, Little change, Longitude, Lower latitude features, Lower latitudes, Magnetic cycle, Magnetic data, Magnetic energy, Magnetic features, Magnetic fields, Magnetic image reconstructions, Magnetic images, Magnetic maps, Magnetic polarity reversal, Magnetic quantities, Magnetic topologies, Magnetic topology, Marsden, Maximum entropy, Maximum entropy brightness, Meridional, Mnras, Monthly notices, Octupole, Octupole components, Other stars, Photospheric temperature, Plasma pressure, Polar spot, Polar spots, Poloidal, Prominence activity, Radial, Radial field, Radial velocity, Radial velocity measurements, Reconstructed, Regularization scheme, Rotation, Rotation rate, Rotational, Rotational modulation, Rotational phase, Rotational phases, S stars, Semel, Signal-to-noise ratio, Source surface, Spectral type, Spectropolarimetric, Spectropolarimetric observations, Spectropolarimetry, Spectroscopical observation, Spherical harmonics, Spot coverage, Spot features, Spot maps, Spot occupancy, Spot topology, Spottedness, Starspots, Stellar, Stellar activity, Stellar convective zone, Stellar latitude, Stellar parameters, Stellar surface, Stokes, Such regions, Such stars, Surface brightness, Temporal evolution, Tentative evidence, Topology, Toroidal, Toroidal components, Waite, Young star, Young stars.
- Teeft :
- Absolute value, Active longitudes, Active stars, April, Average spottedness, Axisymmetric, Azimuthal, Brightness features, Brightness image, Brightness images, Cameron, Collier, Collier cameron, Convective, Convective zone, Convective zone depth, Corona, Coronal, Cutispoto, Data sets, Differential, Differential rotation, Differential rotation measurements, Differential rotation measures, Diger, Dipole component, Donati, Donati collier cameron, Donati landstreet, Donati rees, Donati semel, Doppler, Doppler imaging method, Dynamo, Eld, Ellipse, Emission measure, Epoch, Equatorial rotation period, Error ellipses, Fractional spottedness, Fresnel rhomb, Granzer, High levels, Higher levels, Hillenbrand, Imaging, Imaging code, Inclination angle, Interface layer, Jeffers, Jeffers donati, Latitude, Little change, Longitude, Lower latitude features, Lower latitudes, Magnetic cycle, Magnetic data, Magnetic energy, Magnetic features, Magnetic image reconstructions, Magnetic images, Magnetic maps, Magnetic polarity reversal, Magnetic quantities, Magnetic topologies, Magnetic topology, Marsden, Maximum entropy, Maximum entropy brightness, Meridional, Mnras, Monthly notices, Octupole, Octupole components, Other stars, Photospheric temperature, Plasma pressure, Polar spot, Polar spots, Poloidal, Prominence activity, Radial, Radial velocity, Radial velocity measurements, Reconstructed, Regularization scheme, Rotation, Rotation rate, Rotational, Rotational modulation, Rotational phase, Rotational phases, Semel, Source surface, Spectropolarimetric, Spectropolarimetric observations, Spot coverage, Spot features, Spot maps, Spot occupancy, Spot topology, Spottedness, Stellar, Stellar convective zone, Stellar latitude, Stellar parameters, Stellar surface, Stokes, Such regions, Such stars, Temporal evolution, Tentative evidence, Topology, Toroidal, Toroidal components, Waite, Young star, Young stars.
Abstract
Spectropolarimetric observations of the pre‐main sequence early‐G star HD 141943 were made at three observing epochs (2007, 2009 and 2010). The observations were made using the 3.9‐m Anglo‐Australian Telescope with the UCLES echelle spectrograph and the SEMPOL spectropolarimeter visitor instrument. The brightness and surface magnetic field topologies (given in Paper I) were used to determine the star’s surface differential rotation and reconstruct the coronal magnetic field of the star. The coronal magnetic field at the three epochs shows on the largest scales that the field structure is dominated by the dipole component with possible evidence for the tilt of the dipole axis shifting between observations. We find very high levels of differential rotation on HD 141943 (∼8 times the solar value for the magnetic features and ∼5 times solar for the brightness features), similar to that evidenced by another young early‐G star, HD 171488. These results indicate that a significant increase in the level of differential rotation occurs for young stars around a spectral type of early‐G. We also find for the 2010 observations that there is a large difference in the differential rotation measured from the brightness and magnetic features, similar to that seen on early‐K stars, but with the difference being much larger. We find only tentative evidence for temporal evolution in the differential rotation of HD 141943.
Url:
- https://api.istex.fr/document/BD72C4DFFEB42A575F9A49F4948E83705788A675/fulltext/pdf
- https://api.istex.fr/document/B268DD153113780D608E9AD3AC52D017003C51EB/fulltext/pdf
DOI: 10.1111/j.1365-2966.2011.18272.x
Affiliations:
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J." last="Brown">C. J. Brown</name><affiliation wicri:level="1"><country xml:lang="fr">Australie</country><wicri:regionArea>Faculty of Sciences, University of Southern Queensland, Toowoomba 4350</wicri:regionArea><wicri:noRegion>Toowoomba 4350</wicri:noRegion></affiliation><affiliation wicri:level="1"><country wicri:rule="url">Australie</country></affiliation></author><author><name sortKey="Carter, B D" sort="Carter, B D" uniqKey="Carter B" first="B. D." last="Carter">B. D. Carter</name><affiliation wicri:level="1"><country xml:lang="fr">Australie</country><wicri:regionArea>Faculty of Sciences, University of Southern Queensland, Toowoomba 4350</wicri:regionArea><wicri:noRegion>Toowoomba 4350</wicri:noRegion></affiliation><affiliation wicri:level="1"><country wicri:rule="url">Australie</country></affiliation></author><author><name sortKey="Donati, J" sort="Donati, J" uniqKey="Donati J" first="J." last="Donati">J. Donati</name><affiliation wicri:level="1"><country xml:lang="fr">France</country><wicri:regionArea>LATT–UMR 5572, CNRS & Univ. de Toulouse, 14 Av. E. Belin, F–31400 Toulouse</wicri:regionArea><wicri:noRegion>31400 Toulouse</wicri:noRegion><wicri:noRegion>F–31400 Toulouse</wicri:noRegion></affiliation><affiliation wicri:level="1"><country wicri:rule="url">Australie</country></affiliation></author><author><name sortKey="Dunstone, N" sort="Dunstone, N" uniqKey="Dunstone N" first="N." last="Dunstone">N. Dunstone</name><affiliation></affiliation><affiliation wicri:level="1"><country wicri:rule="url">Australie</country></affiliation></author><author><name sortKey="Hart, R" sort="Hart, R" uniqKey="Hart R" first="R." last="Hart">R. Hart</name><affiliation wicri:level="1"><country xml:lang="fr">Australie</country><wicri:regionArea>Faculty of Sciences, University of Southern Queensland, Toowoomba 4350</wicri:regionArea><wicri:noRegion>Toowoomba 4350</wicri:noRegion></affiliation><affiliation wicri:level="1"><country wicri:rule="url">Australie</country></affiliation></author><author><name sortKey="Semel, M" sort="Semel, M" uniqKey="Semel M" first="M." last="Semel">M. Semel</name><affiliation wicri:level="1"><country xml:lang="fr">France</country><wicri:regionArea>LESIA, Observatoire de Paris‐Meudon, F‐92195 Meudon Cedex</wicri:regionArea><wicri:noRegion>92195 Meudon Cedex</wicri:noRegion><wicri:noRegion>F‐92195 Meudon Cedex</wicri:noRegion></affiliation><affiliation wicri:level="1"><country wicri:rule="url">Australie</country></affiliation></author><author><name sortKey="Waite, I A" sort="Waite, I A" uniqKey="Waite I" first="I. A." last="Waite">I. A. Waite</name><affiliation wicri:level="1"><country xml:lang="fr">Australie</country><wicri:regionArea>Faculty of Sciences, University of Southern Queensland, Toowoomba 4350</wicri:regionArea><wicri:noRegion>Toowoomba 4350</wicri:noRegion></affiliation><affiliation wicri:level="1"><country wicri:rule="url">Australie</country></affiliation></author></analytic><monogr></monogr><series><title level="j" type="main">Monthly Notices of the Royal Astronomical Society</title><title level="j" type="alt">MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY</title><idno type="ISSN">0035-8711</idno><idno type="eISSN">1365-2966</idno><imprint><biblScope unit="vol">413</biblScope><biblScope unit="issue">3</biblScope><biblScope unit="page" from="1939">1939</biblScope><biblScope unit="page" to="1948">1948</biblScope><biblScope unit="page-count">10</biblScope><publisher>Blackwell Publishing Ltd</publisher><pubPlace>Oxford, UK</pubPlace><date type="published" 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measures</term><term>Diger</term><term>Dipole component</term><term>Dipoles</term><term>Donati</term><term>Donati collier cameron</term><term>Donati landstreet</term><term>Donati rees</term><term>Donati semel</term><term>Doppler</term><term>Doppler imaging method</term><term>Dynamo</term><term>Eld</term><term>Ellipse</term><term>Emission measure</term><term>Epoch</term><term>Equatorial rotation period</term><term>Error ellipses</term><term>Field emission</term><term>Fractional spottedness</term><term>Fresnel rhomb</term><term>G stars</term><term>Granzer</term><term>H-alpha lines</term><term>High levels</term><term>Higher levels</term><term>Hillenbrand</term><term>Imaging</term><term>Imaging code</term><term>Inclination angle</term><term>Interface layer</term><term>Jeffers</term><term>Jeffers donati</term><term>K stars</term><term>Latitude</term><term>Line shape</term><term>Little change</term><term>Longitude</term><term>Lower latitude features</term><term>Lower latitudes</term><term>Magnetic cycle</term><term>Magnetic data</term><term>Magnetic energy</term><term>Magnetic features</term><term>Magnetic fields</term><term>Magnetic image reconstructions</term><term>Magnetic images</term><term>Magnetic maps</term><term>Magnetic polarity reversal</term><term>Magnetic quantities</term><term>Magnetic topologies</term><term>Magnetic topology</term><term>Marsden</term><term>Maximum entropy</term><term>Maximum entropy brightness</term><term>Meridional</term><term>Mnras</term><term>Monthly notices</term><term>Octupole</term><term>Octupole components</term><term>Other stars</term><term>Photospheric temperature</term><term>Plasma pressure</term><term>Polar spot</term><term>Polar spots</term><term>Poloidal</term><term>Prominence activity</term><term>Radial</term><term>Radial field</term><term>Radial velocity</term><term>Radial velocity measurements</term><term>Reconstructed</term><term>Regularization scheme</term><term>Rotation</term><term>Rotation rate</term><term>Rotational</term><term>Rotational modulation</term><term>Rotational phase</term><term>Rotational phases</term><term>S stars</term><term>Semel</term><term>Signal-to-noise ratio</term><term>Source surface</term><term>Spectral type</term><term>Spectropolarimetric</term><term>Spectropolarimetric observations</term><term>Spectropolarimetry</term><term>Spectroscopical observation</term><term>Spherical harmonics</term><term>Spot coverage</term><term>Spot features</term><term>Spot maps</term><term>Spot occupancy</term><term>Spot topology</term><term>Spottedness</term><term>Starspots</term><term>Stellar</term><term>Stellar activity</term><term>Stellar convective zone</term><term>Stellar latitude</term><term>Stellar parameters</term><term>Stellar surface</term><term>Stokes</term><term>Such regions</term><term>Such stars</term><term>Surface brightness</term><term>Temporal evolution</term><term>Tentative evidence</term><term>Topology</term><term>Toroidal</term><term>Toroidal components</term><term>Waite</term><term>Young star</term><term>Young stars</term></keywords><keywords scheme="Pascal" xml:lang="fr"><term>Activité stellaire</term><term>Brillance surface</term><term>Champ azimutal</term><term>Champ magnétique</term><term>Champ radial</term><term>Dipôle</term><term>Distribution brillance</term><term>Déconvolution</term><term>Emission champ</term><term>Etoile G</term><term>Etoile K</term><term>Etoile S</term><term>Etoile jeune</term><term>Harmonique sphérique</term><term>Observation spectroscopique</term><term>Profil raie</term><term>Raie H alpha</term><term>Rapport signal bruit</term><term>Rotation différentielle</term><term>Spectropolarimétrie</term><term>Tache stellaire</term><term>Topologie</term><term>Type spectral</term></keywords><keywords scheme="Teeft" xml:lang="en"><term>Absolute value</term><term>Active longitudes</term><term>Active stars</term><term>April</term><term>Average spottedness</term><term>Axisymmetric</term><term>Azimuthal</term><term>Brightness features</term><term>Brightness image</term><term>Brightness images</term><term>Cameron</term><term>Collier</term><term>Collier cameron</term><term>Convective</term><term>Convective zone</term><term>Convective zone depth</term><term>Corona</term><term>Coronal</term><term>Cutispoto</term><term>Data sets</term><term>Differential</term><term>Differential rotation</term><term>Differential rotation measurements</term><term>Differential rotation measures</term><term>Diger</term><term>Dipole component</term><term>Donati</term><term>Donati collier cameron</term><term>Donati landstreet</term><term>Donati rees</term><term>Donati semel</term><term>Doppler</term><term>Doppler imaging method</term><term>Dynamo</term><term>Eld</term><term>Ellipse</term><term>Emission measure</term><term>Epoch</term><term>Equatorial rotation period</term><term>Error ellipses</term><term>Fractional spottedness</term><term>Fresnel rhomb</term><term>Granzer</term><term>High levels</term><term>Higher levels</term><term>Hillenbrand</term><term>Imaging</term><term>Imaging code</term><term>Inclination angle</term><term>Interface layer</term><term>Jeffers</term><term>Jeffers donati</term><term>Latitude</term><term>Little change</term><term>Longitude</term><term>Lower latitude features</term><term>Lower latitudes</term><term>Magnetic cycle</term><term>Magnetic data</term><term>Magnetic energy</term><term>Magnetic features</term><term>Magnetic image reconstructions</term><term>Magnetic images</term><term>Magnetic maps</term><term>Magnetic polarity reversal</term><term>Magnetic quantities</term><term>Magnetic topologies</term><term>Magnetic topology</term><term>Marsden</term><term>Maximum entropy</term><term>Maximum entropy brightness</term><term>Meridional</term><term>Mnras</term><term>Monthly notices</term><term>Octupole</term><term>Octupole components</term><term>Other stars</term><term>Photospheric temperature</term><term>Plasma pressure</term><term>Polar spot</term><term>Polar spots</term><term>Poloidal</term><term>Prominence activity</term><term>Radial</term><term>Radial velocity</term><term>Radial velocity measurements</term><term>Reconstructed</term><term>Regularization scheme</term><term>Rotation</term><term>Rotation rate</term><term>Rotational</term><term>Rotational modulation</term><term>Rotational phase</term><term>Rotational phases</term><term>Semel</term><term>Source surface</term><term>Spectropolarimetric</term><term>Spectropolarimetric observations</term><term>Spot coverage</term><term>Spot features</term><term>Spot maps</term><term>Spot occupancy</term><term>Spot topology</term><term>Spottedness</term><term>Stellar</term><term>Stellar convective zone</term><term>Stellar latitude</term><term>Stellar parameters</term><term>Stellar surface</term><term>Stokes</term><term>Such regions</term><term>Such stars</term><term>Temporal evolution</term><term>Tentative evidence</term><term>Topology</term><term>Toroidal</term><term>Toroidal components</term><term>Waite</term><term>Young star</term><term>Young stars</term></keywords></textClass></profileDesc></teiHeader><front><div type="abstract" xml:lang="en">Spectropolarimetric observations of the pre‐main sequence early‐G star HD 141943 were made at three observing epochs (2007, 2009 and 2010). The observations were made using the 3.9‐m Anglo‐Australian Telescope with the UCLES echelle spectrograph and the SEMPOL spectropolarimeter visitor instrument. The brightness and surface magnetic field topologies (given in Paper I) were used to determine the star’s surface differential rotation and reconstruct the coronal magnetic field of the star. The coronal magnetic field at the three epochs shows on the largest scales that the field structure is dominated by the dipole component with possible evidence for the tilt of the dipole axis shifting between observations. We find very high levels of differential rotation on HD 141943 (∼8 times the solar value for the magnetic features and ∼5 times solar for the brightness features), similar to that evidenced by another young early‐G star, HD 171488. These results indicate that a significant increase in the level of differential rotation occurs for young stars around a spectral type of early‐G. We also find for the 2010 observations that there is a large difference in the differential rotation measured from the brightness and magnetic features, similar to that seen on early‐K stars, but with the difference being much larger. We find only tentative evidence for temporal evolution in the differential rotation of HD 141943.</div></front></TEI><affiliations><list><country><li>Australie</li><li>France</li></country><region><li>Auvergne-Rhône-Alpes</li><li>Rhône-Alpes</li></region><settlement><li>Grenoble</li></settlement><orgName><li>Université Joseph Fourier</li></orgName></list><tree><country name="Australie"><noRegion><name sortKey="Marsden, S C" sort="Marsden, S C" uniqKey="Marsden S" first="S. C." last="Marsden">S. C. Marsden</name></noRegion><name sortKey="Alecian, E" sort="Alecian, E" uniqKey="Alecian E" first="E." last="Alecian">E. Alecian</name><name sortKey="Brown, C J" sort="Brown, C J" uniqKey="Brown C" first="C. J." last="Brown">C. J. Brown</name><name sortKey="Brown, C J" sort="Brown, C J" uniqKey="Brown C" first="C. J." last="Brown">C. J. Brown</name><name sortKey="Carter, B D" sort="Carter, B D" uniqKey="Carter B" first="B. D." last="Carter">B. D. Carter</name><name sortKey="Carter, B D" sort="Carter, B D" uniqKey="Carter B" first="B. D." last="Carter">B. D. Carter</name><name sortKey="Donati, J" sort="Donati, J" uniqKey="Donati J" first="J." last="Donati">J. Donati</name><name sortKey="Dunstone, N" sort="Dunstone, N" uniqKey="Dunstone N" first="N." last="Dunstone">N. Dunstone</name><name sortKey="Hart, R" sort="Hart, R" uniqKey="Hart R" first="R." last="Hart">R. Hart</name><name sortKey="Hart, R" sort="Hart, R" uniqKey="Hart R" first="R." last="Hart">R. Hart</name><name sortKey="Jardine, M M" sort="Jardine, M M" uniqKey="Jardine M" first="M. M." last="Jardine">M. M. Jardine</name><name sortKey="Marsden, S C" sort="Marsden, S C" uniqKey="Marsden S" first="S. C." last="Marsden">S. C. Marsden</name><name sortKey="Marsden, S C" sort="Marsden, S C" uniqKey="Marsden S" first="S. C." last="Marsden">S. C. Marsden</name><name sortKey="Ramirez Velez, J C" sort="Ramirez Velez, J C" uniqKey="Ramirez Velez J" first="J. C." last="Ramírez Vélez">J. C. Ramírez Vélez</name><name sortKey="Semel, M" sort="Semel, M" uniqKey="Semel M" first="M." last="Semel">M. Semel</name><name sortKey="Waite, I A" sort="Waite, I A" uniqKey="Waite I" first="I. A." last="Waite">I. A. Waite</name><name sortKey="Waite, I A" sort="Waite, I A" uniqKey="Waite I" first="I. A." last="Waite">I. A. Waite</name></country><country name="France"><noRegion><name sortKey="Ramirez Velez, J C" sort="Ramirez Velez, J C" uniqKey="Ramirez Velez J" first="J. C." last="Ramírez Vélez">J. C. Ramírez Vélez</name></noRegion><name sortKey="Alecian, E" sort="Alecian, E" uniqKey="Alecian E" first="E." last="Alecian">E. Alecian</name><name sortKey="Alecian, E" sort="Alecian, E" uniqKey="Alecian E" first="E." last="Alecian">E. Alecian</name><name sortKey="Donati, J" sort="Donati, J" uniqKey="Donati J" first="J." last="Donati">J. Donati</name><name sortKey="Semel, M" sort="Semel, M" uniqKey="Semel M" first="M." last="Semel">M. Semel</name></country></tree></affiliations></record>Pour manipuler ce document sous Unix (Dilib)
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|texte= Magnetic fields and differential rotation on the pre‐main sequence – II. The early‐G star HD 141943 – coronal magnetic field, Hα emission and differential rotation
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