Large-scale magnetic topologies of late M dwarfs⋆

  title={Large-scale magnetic topologies of late M dwarfs⋆},
  author={Julien Morin and Jean-François Donati and Pascal Petit and Xavier Delfosse and Thierry Forveille and Loic Albert and Michel Auri{\`e}re and R{\'e}mi Cabanac and Boris Dintrans and R Fares and Thomas Gastine and Moira M. Jardine and François Lignières and F. Paletou and J. C. Ram{\'i}rez V{\'e}lez and Sylvie Th{\'e}ado},
  journal={arXiv: Astrophysics},
We 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. 2008b; Morin et al. 2008b) 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… 

Large-scale magnetic topologies of late M dwarfs★: Magnetic topologies of late M dwarfs

We 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

Large-scale magnetic topologies of early M dwarfs

We present here additional results of a spectropolarimetric survey of a small sample of stars ranging from spectral type M0 to M8 aimed at investigating observationally how dynamo processes operate

Large-scale magnetic fields of low-mass dwarfs: the many faces of dynamo

  • J. Donati
  • Physics
    Proceedings of the International Astronomical Union
  • 2010
Abstract Magnetic field are ubiquitous to low-mass stars and can potentially impact their evolution and their internal structure; yet the physical processes (called dynamo) that succeed at generating


The magnetic field topology plays an important role in the understanding of stellar magnetic activity. While it is widely accepted that the dynamo action present in low-mass partially convective

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Magnetic fields of low-mass stars & protostars. Observations & results

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We present a new method for direct measurement of magnetic fields on ultracool stars and brown dwarfs. It takes advantage of the Wing-Ford bands of FeH, which are seen throughout the M and L spectral

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The results, which demonstrate that fully convective stars are able to trigger axisymmetric large-scale poloidal fields without differential rotation, challenge existing theoretical models of field generation in cool stars.

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With a Jupiter-mass planet orbiting at a distance of only 0.031 AU, the active K2 dwarf HD 189733 is a potential candidate in which to study the magnetospheric interactions of a cool star with its

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It is thought that the large-scale solar-cycle magnetic field is generated in a thin region at the interface of the radiative core (RC) and solar convection zone (SCZ). We show that the bulk of the