English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

(abridged) Context: Main-sequence late-type stars with masses less than $0.35M_\odot$ are fully convective. Aims: The goal is to study convection,differential rotation, and dynamos as functions of rotation in fully convectivestars. Methods: Three-dimensional hydrodynamic and magnetohydrodynamicnumerical simulations with a star-in-a-box model, where a spherical star isimmersed inside of a Cartesian cube, are used. The model corresponds to a$0.2M_\odot$ M5 dwarf. Rotation periods ($P_{\rm rot}$) between 4.3 and 430days are explored. Results: The slowly rotating model with $P_{\rm rot}=430$days produces anti-solar differential rotation with a slow equator and fastpoles, along with predominantly axisymmetric quasi-steady large-scale magneticfields. For intermediate rotation ($P_{\rm rot}=144$ and $43$ days)differential rotation is solar-like (fast equator, slow poles) and large-scalemagnetic fields are mostly axisymmetric and either quasi-stationary or cyclic.The latter occurs in a similar parameter regime as in other numerical studiesin spherical shells, and the cycle period is similar to observed cycles infully convective stars with comparable $P_{\rm rot}$. In the rapid rotationregime the differential rotation is weak and the large-scale magnetic fieldsare increasingly non-axisymmetric with a dominating $m=1$ mode. Thislarge-scale non-axisymmetric field also exhibits azimuthal dynamo waves.Conclusions: The results of the star-in-a-box models agree with simulations ofpartially convective late-type stars in spherical shells in that thetransitions in differential rotation and dynamo regimes occur at similarrotational regimes in terms of the Coriolis (inverse Rossby) number. Thissimilarity between partially and fully convective stars suggests that theprocesses generating differential rotation and large-scale magnetism areinsensitive to the geometry of the star.

Star-in-a-box simulations of fully convective stars