Related papers: Single-hemisphere dynamos in M-dwarf stars
The study of rotation and activity in low-mass stars or brown dwarfs of spectral classes M and L has seen enormous progress during the last years. I summarize the results from different works that measured activity, rotation, and sometimes…
The rotation-activity connection explains stellar activity in terms of rotation and convective overturn time. It is well established in stars of spectral types F--K and in M-type stars of young clusters. It is not established in field…
(abridged) Context: Main-sequence late-type stars with masses less than $0.35 M_\odot$ are fully convective. Aims: The goal is to study convection, differential rotation, and dynamos as functions of rotation in fully convective stars.…
A convection-driven MHD dynamo in a rotating spherical shell, with clearly defined structural elements in the flow and magnetic field, is simulated numerically. Such dynamos can be called deterministic, in contrast to those explicitly…
Context: dynamo action in giant planets and rapidly rotating stars leads to a broad variety of magnetic field geometries including small scale multipolar and large scale dipole-dominated topologies. Previous dynamo models suggest that…
We have examined the relationship between rotation and activity in 14 late-type (M6-M7) M dwarfs, using high resolution spectra taken at the Keck Observatory and flux-calibrated spectra from the Sloan Digital Sky Survey. Most are inactive…
The regulation of angular momentum is one of the key processes for our understanding of stellar evolution. In contrast to solar-mass stars, very low mass (VLM) objects and brown dwarfs are believed to be fully convective. This may lead to…
Fully convective M dwarfs typically remain rapidly rotating and magnetically active for billions of years, followed by an abrupt and mass-dependent transition to slow rotation and quiescence. A robust understanding of this process is…
We study the interaction between the atmospheres of Venus-like, non-magnetized exoplanets orbiting an M-dwarf star, and the stellar wind using a multi-species Magnetohydrodynaic (MHD) model. We focus our investigation on the effect of…
The high-energy emission from low-mass stars is mediated by the magnetic dynamo. Although the mechanisms by which fully convective stars generate large-scale magnetic fields are not well understood, it is clear that, as for solar-type…
M-dwarf stars provide very favourable conditions to find habitable worlds beyond our solar system. The estimation of the fundamental parameters of the transiting exoplanets rely on the accuracy of the theoretical predictions for radius and…
Stars are changing entities in a constant evolution during their lives. At non-secular time scales (from seconds to years) the effect of dynamical processes such as convection, rotation, and magnetic fields can modify the stellar…
M dwarf stars are currently the main targets in searches for potentially habitable planets. However, their winds have been suggested to be harmful to planetary atmospheres. Here, in order to better understand the winds of M dwarfs and also…
We have carried out numerical simulations of the convection zone in a K dwarf of 0.7 solar masses rotating at the solar rotation period. We study the convection pattern, the differential rotation and meridional flows, and the…
The difference in stellar structure above and below spectral type ~M4 is expected to be a very important one, connected directly or indirectly to a variety of observational phenomena in cool stars---such as rotation, activity, magnetic…
The recent detections of temperate terrestrial planets orbiting nearby stars and the promise of characterizing their atmospheres motivates a need to understand how the diversity of possible planetary parameters affects the climate of…
We review the current state of knowledge of magnetic fields inside stars, concentrating on recent developments concerning magnetic fields in stably stratified (zones of) stars, leaving out convective dynamo theories and observations of…
We carried out 3D radiative magnetohydrodynamic simulations of the convective and magnetic structure in the surface layers (uppermost part of the convection zone and photosphere) of main-sequence stars of spectral types F3 to M2. The…
The vast majority of stars in the nearby stellar neighborhood are M dwarfs. Their low masses and luminosities result in slow rates of nuclear evolution and minimal changes to the star's observable properties, even along astronomical…
Magnetic fields can be created in stably stratified (non-convective) layers in a differentially rotating star. A magnetic instability in the toroidal field (wound up by differential rotation) replaces the role of convection in closing the…