@article{12718,
  author = {Allan Brun and Antoine Strugarek and Quentin Noraz and Barbara Perri and Jacobo Varela and Kyle Augsutson and Paul Charbonneau and Juri Toomre},
  title = {Powering Stellar Magnetism: Energy Transfers in Cyclic Dynamos of Sun-like Stars},
  abstract = {We use the ASH code to model the convective dynamo of solar-type stars. Based on a series of 15 3-D MHD simulations spanning 4 bins in rotation and mass, we show what mechanisms are at work in these stellar dynamos with and without magnetic cycles and how global stellar parameters affect the outcome. We also derive scaling laws for the differential rotation and magnetic field based on these simulations. We find a weaker trend between differential rotation and stellar rotation rate, (ΔΩ∼(|Ω|/Ω⊙)0.46) in the MHD solutions than in their HD counterpart (|Ω|/Ω⊙)0.66), yielding a better agreement with the observational trends based on power laws. We find that for a fluid Rossby number between 0.15≲Rof≲0.65 the solutions possess long magnetic cycle, if Rof≲0.42 a short cycle and if Rof≳1 (anti-solar-like differential rotation) a statistically steady state. We show that short-cycle dynamos follow the classical Parker-Yoshimura rule whereas the long-cycle period ones do not. We further demonstrate that the Rossby number dependency of the large-scale surface magnetic field in the simulation (BL,surf∼Ro−1.26f) agrees better with observations (BV∼Ro−1.4±0.1s) and differs from dynamo scaling based on the global magnetic energy (Bbulk∼Ro−0.5f). We also show that up to few percents of the stellar luminosity can be channelled into the star's magnetism, hence providing a large energy reservoir for possible surface eruptive events.},
  year = {2022},
  journal = {The Astrophysical Journal},
  volume = {926},
  month = {2022-02},
  url = {https://iopscience.iop.org/article/10.3847/1538-4357/ac469b/meta},
  doi = {10.3847/1538-4357/ac469b/meta},
}