Related papers: Spin-down by dynamo action in simulated radiative …
Unveiling the evolution of toroidal field instability, known as Tayler instability, is essential to understand the strength and topology of the magnetic fields observed in early-type stars, in the core of the red giants, or in any stellar…
Magnetic fields in nearby, star-forming galaxies reveal both large-scale patterns and small-scale structures. A large-scale field reversal may exist in the Milky Way but no such reversals have been observed so far in external galaxies. The…
An update is given on the current status of solar and stellar dynamos. At present, it is still unclear why stellar cycle frequencies increase with rotation frequency in such a way that their ratio increases with stellar activity. The…
Neutron stars such as pulsars and magnetars lose angular momentum primarily through electromagnetic dipole radiation, gravitational waves, $r$-mode oscillation, and also affected by fallback accretion processes. However, anomalous spin…
Many types of stars have strong magnetic fields that can dynamically influence the flow of circumstellar matter. In stars with accretion disks, the stellar magnetic field can truncate the inner disk and determine the paths that matter can…
Magnetism can greatly impact the evolution of stars. In some stars with OBA spectral types there is direct evidence via the Zeeman effect for stable, large-scale magnetospheres, which lead to the spin-down of the stellar surface and reduced…
The origin and evolution of magnetic fields in the Universe is still an open question. Their observations in galaxies suggest strong magnetic fields already at high redshift as well as at present time. However, neither primordial magnetic…
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…
The topic of turbulent transport in a stellar radiative zone is vast and poorly understood. Many physical processes can potentially drive turbulence in stellar radiative zone but the limited observational constraints and the uncertainties…
The exteriors of stellar and galactic dynamos are usually modeled as current-free potential fields. A more realistic description might instead be that of a force-free magnetic field. Here, we suggest that, in the absence of outflows,…
Magnetic buoyancy is believed to drive the transport of magnetic flux tubes from the convection zone to the surface of the Sun. The magnetic fields form twisted loop-like structures in the solar atmosphere. In this paper we use helical…
A fundamental property of molecular clouds is that they are turbulent, but how this turbulence is generated and maintained is unknown. One possibility is that stars forming within the cloud regenerate turbulence via their outflows, winds…
A model is developed for magnetic `propeller'-driven outflows which cause a rapidly rotating magnetized star accreting from a disk to spin-down. Energy and angular momentum lost by the star goes into expelling most of the accreting disk…
We investigate the chiral magnetic instability in the crust of a neutron star as a potential mechanism for amplifying magnetic fields. This instability may become active when small deviations from chemical equilibrium are sustained over…
Observations of surface magnetic fields are now within reach for many stellar types thanks to the development of Zeeman-Doppler Imaging. These observations are extremely useful for constraining rotational evolution models of stars, as well…
Magnetic fields are observed in star forming regions. However simulations of the late stages of star formation that do not include magnetic fields provide a good fit to the properties of young stars including the initial mass function (IMF)…
Are magnetic fields important in primordial star formation? Assuming that star formation occurs via an accretion disk that is turbulent, initially because of local gravitational instability, we calculate the disk structure for realistic…
Magnetic fields play a role in almost all stages of stellar evolution. Most low-mass stars, including the Sun, show surface fields that are generated by dynamo processes in their convective envelopes. Intermediate-mass stars do not have…
Nearly all of the initial angular momentum of the matter that goes into each forming star must somehow be removed or redistributed during the formation process. The possible transport mechanisms and the possible fates of the excess angular…
We review some of the recent progress on modeling planetary and stellar dynamos. Particular attention is given to the dynamo mechanisms and the resulting properties of the field. We present direct numerical simulations using a simple…