The magnetic and spin-down properties of slowly rotating fully convective M dwarfs
ABSTRACT The evolution of the magnetism, winds, and rotation of low-mass stars are all linked. One of the most common ways to probe the magnetic properties of low-mass stars is with the Zeeman–Doppler imaging (ZDI) technique. The magnetic properties of partially convective stars has been relatively well explored with the ZDI technique, but the same is not true of fully convective stars. In this work, we analyse a sample of stars that have been mapped with ZDI. Notably, this sample contains a number of slowly rotating fully convective M dwarfs whose magnetic fields were recently reconstructed with ZDI. We find that the dipolar, quadrupolar, and octupolar field strengths of the slowly rotating fully convective stars do not follow the same Rossby number scaling in the unsaturated regime as partially convective stars. Based on these field strengths, we demonstrate that previous estimates of spin-down torques for slowly rotating fully convective stars could have been underestimated by an order of magnitude or more. Additionally, we also find that fully convective and partially convective stars fall into distinct sequences when comparing their poloidal and toroidal magnetic energies.
Authors
- Louis Amard (ORCID: https://orcid.org/0000-0003-2508-6093)
- K. T. Smith
- Baptiste Klein (ORCID: https://orcid.org/0000-0003-0637-5236)
- L T Lehmann (ORCID: https://orcid.org/0000-0001-7264-0734)
- Victor See (ORCID: https://orcid.org/0000-0001-5986-3423)
- C. P. Folsom (ORCID: https://orcid.org/0000-0002-9023-7890)
- J.‐F. Donati (ORCID: https://orcid.org/0000-0001-5541-2887)
- E. L. Brown (ORCID: https://orcid.org/0000-0002-4650-2087)
- I. A. Waite (ORCID: https://orcid.org/0000-0002-3249-3538)
- R. Farès (ORCID: https://orcid.org/0000-0002-3301-341X)
- S. V. Jeffers (ORCID: https://orcid.org/0000-0003-2490-4779)
- J. Morin (ORCID: https://orcid.org/0000-0002-4996-6901)
- S. C. Marsden (ORCID: https://orcid.org/0000-0001-5522-8887)
- S. Bellotti (ORCID: https://orcid.org/0000-0002-2558-6920)
- M. Jardine (ORCID: https://orcid.org/0000-0002-1466-5236)
- Adam J. Finley (ORCID: https://orcid.org/0000-0002-3020-9409)
- Matthew W. Mengel (ORCID: https://orcid.org/0000-0002-7830-6822)
- A. A. Vidotto (ORCID: https://orcid.org/0000-0001-5371-2675)
- P. Petit (ORCID: https://orcid.org/0000-0001-7624-9222)
- Sean P. Matt (ORCID: https://orcid.org/0000-0001-9590-2274)
- Élodie M Hébrard
Institutions
- University of Geneva (CH)
- Leiden University (NL)
- Centre National de la Recherche Scientifique (FR)
- University of Vienna (AT)
- Université Toulouse III - Paul Sabatier (FR)
- Al Ain University (AE)
- The University of Queensland (AU)
- University of St Andrews (GB)
- Université Fédérale de Toulouse Midi-Pyrénées (FR)
- University of Southern Queensland (AU)
- Université de Montpellier (FR)
- United Arab Emirates University (AE)
- Université Paris Cité (FR)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Université Paris-Saclay (FR)
- Tartu Observatory (EE)
- University of Oxford (GB)
- Astrophysique, Instrumentation et Modélisation (FR)
- Laboratoire Univers et Particules de Montpellier (FR)
- CEA Paris-Saclay (FR)
- Thüringer Landessternwarte Tautenburg (DE)
- European Space Research and Technology Centre (NL)
- Central Queensland University (AU)
- University of Birmingham (GB)
- University of Oklahoma (US)
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society
- Published
- 2025-07-19
- DOI
- https://doi.org/10.1093/mnras/staf1197
- Citations
- 4
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 4.62