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Related papers: Exploring the Role of a Tachocline in M-Dwarf Magn…

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In recent years, observers have found that the fraction of M-stars demonstrating significant magnetic activity transitions sharply from roughly $10\%$ for main-sequence stars earlier (more massive) than spectral type M3.5 (0.35 M$_\odot$)…

Solar and Stellar Astrophysics · Physics 2020-04-23 Connor P. Bice , Juri Toomre

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 in stars on both sides of the full…

In the canonical theory of stellar magnetic dynamo, the tachocline in partially convective stars serves to arrange small-scale fields, generated by stochastic movement of plasma into a coherent large-scale field. Mid-to-late M-dwarfs, which…

Solar and Stellar Astrophysics · Physics 2023-06-02 Emily M. Boudreaux , Elisabeth R. Newton , Nicholas Mondrik , David Charbonneau , Jonathan Irwin

Rapidly rotating late M dwarfs are observed in two different branches of magnetic activity, although they operate in the same stellar parameter range. Current empirical evidence indicates that M dwarfs with spectral types ranging from M3 /…

Solar and Stellar Astrophysics · Physics 2025-11-18 Giuseppina Nigro , Francesco Berrilli , Giuseppe Bono , Dario Del Moro , Luca Giovannelli , Valentina Penza , Raffaele Reda

We present here the first results of a spectropolarimetric analysis of a small sample (about 20) of active stars ranging from spectral type M0 to M8, which are either fully-convective or possess a very small radiative core. This study aims…

Astrophysics · Physics 2014-11-18 J. Morin , J. -F. Donati , X. Delfosse , T. Forveille , M. M. Jardine

We present in this paper the first results of a spectropolarimetric analysis of a small sample (~ 20) of active stars ranging from spectral type M0 to M8, which are either fully-convective or possess a very small radiative core. This study…

Close M-dwarf binaries and higher multiples allow the investigation of rotational evolution and mean magnetic flux unbiased from scatter in inclination angle and age since the orientation of the spin axis of the components is most likely…

Solar and Stellar Astrophysics · Physics 2015-05-30 D. Shulyak , A. Seifahrt , A. Reiners , O. Kochukhov , N. Piskunov

M dwarfs are the most numerous stars in our Galaxy with masses between approximately 0.5 and 0.1 solar mass. Many of them show surface activity qualitatively similar to our Sun and generate flares, high X-ray fluxes, and large-scale…

Solar and Stellar Astrophysics · Physics 2018-01-29 D. Shulyak A. Reiners , A. Engeln , L. Malo , R. Yadav , J. Morin , O. Kochukhov

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).…

Solar and Stellar Astrophysics · Physics 2010-06-28 J. Morin , J. F. Donati , P. Petit , X. Delfosse , T. Forveille , M. M. Jardine

M-dwarf stars are well known for the intense magnetic activity that many of them exhibit. In cool stars with near-surface convection zones, this magnetic activity is thought to be driven largely by the interplay of convection and the large…

Solar and Stellar Astrophysics · Physics 2022-03-30 Connor P. Bice , Juri Toomre

M dwarfs are low-mass main-sequence stars, the most numerous type of stars in the solar neighbourhood, which are known to have significant magnetic activity. The aim of this work is to explore the dynamo solutions and magnetic fields of…

Solar and Stellar Astrophysics · Physics 2022-06-29 Carolina A. Ortiz-Rodríguez , Dominik R. G. Schleicher , Petri J. Käpylä , Felipe H. Navarrete

M dwarfs are the most abundant stars in the Galaxy and exhibit diverse magnetic behaviours. Understanding their large-scale magnetic fields is essential to study stellar dynamos and assess the impact of magnetic activity on planetary…

M dwarfs remain active over longer timescales than their Sunlike counterparts, with potentially devastating implications for the atmospheres of their planets. However, the age at which fully-convective M dwarfs transition from active and…

Solar and Stellar Astrophysics · Physics 2022-09-14 Emily K. Pass , David Charbonneau , Jonathan M. Irwin , Jennifer G. Winters

Stellar activity and rotation frustrate the detection of exoplanets through the radial velocity technique. This effect is particularly of concern for M dwarfs, which can remain magnetically active for billions of years. We compile rotation…

Earth and Planetary Astrophysics · Physics 2016-04-27 Elisabeth R. Newton , Jonathan Irwin , David Charbonneau , Zachory K. Berta-Thompson , Jason A. Dittmann

We present three-dimensional nonlinear magnetohydrodynamic simulations of the interiors of fully convective M-dwarfs. Our models consider 0.3 solar-mass stars using the Anelastic Spherical Harmonic code, with the spherical computational…

Astrophysics · Physics 2009-11-13 Matthew Browning

M-dwarfs demonstrate two types of activity: 1) strong (kilogauss) almost axisymmetric poloidal magnetic fields; and 2) considerably weaker nonaxisymmetric fields, sometimes including a substantial toroidal component. Dynamo bistability has…

Solar and Stellar Astrophysics · Physics 2015-06-18 L. L. Kitchatinov , D. Moss , D. Sokoloff

Recent observations indicate that fully convective stars can effectively build magnetic fields without the aid of a tachocline of shear, that those fields can possess large-scale components, and that they may sense the effects of rotation.…

Astrophysics · Physics 2009-11-13 Matthew Browning , Gibor Basri

We perform three-dimensional numerical simulations of stellar winds of early-M dwarf stars. Our simulations incorporate observationally reconstructed large-scale surface magnetic maps, suggesting that the complexity of the magnetic field…

Solar and Stellar Astrophysics · Physics 2015-06-18 A. A. Vidotto , M. Jardine , J. Morin , J. F. Donati , M. Opher , T. I. Gombosi

Recent observations of the magnetic field in pre-main sequence stars suggest that the magnetic field topology changes as a function of age. The presence of a tachocline could be an important factor in the development of magnetic field with…

Solar and Stellar Astrophysics · Physics 2017-11-07 Bonnie Zaire , Gustavo Guerrero , Alexander Kosovichev , Piotr Smolarkiewicz , Natalia Landin

M-dwarf stars below a certain mass are convective from their cores to their photospheres. These fully convective objects are extremely numerous, very magnetically active, and the likely hosts of many exoplanets. Here we study, for the first…

Solar and Stellar Astrophysics · Physics 2020-10-14 Benjamin P. Brown , Jeffrey S. Oishi , Geoffrey M. Vasil , Daniel Lecoanet , Keaton J. Burns
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