相关论文: Magnetic Interaction between Stars and Accretion D…
This article reviews our current understanding of modelling convection dynamics in stars. Several semi-analytical time-dependent convection models have been proposed for pulsating one-dimensional stellar structures with different…
The propeller regime of disk accretion to a rapidly rotating magnetized star is investigated here for the first time by axisymmetric 2.5D magnetohydrodynamic simulations. An expanded, closed magnetosphere forms in which the magnetic field…
We discuss how recent advances in observations, theory and numerical simulations have allowed the stellar community to progress in its understanding of stellar convection, rotation and magnetism and to assess the degree to which the Sun and…
We formulate a general, steady-state model for the torque on a magnetized star from a surrounding accretion disc. For the first time, we include the opening of dipolar magnetic field lines due to the differential rotation between the star…
Stars interact with their planets through gravitation, radiation, and magnetic fields. I shall focus on the interactions between late-type stars with an outer convection zone and close-in planets, i.e., with an orbital semimajor axis…
The problem of interaction of the rotating magnetic field, frozen to a star, with a thin well conducting accretion disk is solved exactly. It is shown that a disk pushes the magnetic field lines towards a star, compressing the stellar…
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…
We examine 3 analytic theories of magnetospheric accretion onto classical T Tauri stars under the assumption that the magnetic field strength does not vary appreciably from star to star. From these investigations we derive predicted…
In this lecture I review the theory of magnetized accretion discs driving jets, with a focus on Young Stellar Objects (YSOs). I first introduce observational and theoretical arguments in favor of the ``disc wind'' paradigm. There, accretion…
A-type stars have a complex internal structure with the possibility of multiple convection zones. If not sufficiently separated, such zones will interact through the convectively stable regions that lie between them. It is therefore of…
Evidence of magnetic interaction between late-type stars and close-in giant planets is provided by the observations of stellar hot spots rotating synchronously with the planets and showing an enhancement of chromospheric and X-ray fluxes.…
We obtained equations for a thin magnetic accretion disk, using the method of asymptotic approximation. They cannot be solved analytically-without solutions for a magnetic field in the magnetosphere between the star and the disk, only a set…
It has been proposed that magnetic activity could be enhanced due to interactions between close-in massive planets and their host stars. In this article, I present a brief overview of the connection between stellar magnetic activity and…
Stars and their exoplanets evolve together. Depending on the physical characteristics of these systems, such as age, orbital distance and activity of the host stars, certain types of star-exoplanet interactions can dominate during given…
We discuss possible mechanisms underlying the observed features of stellar activity cycles, such as multiple periodicities in very active stars, non-cyclic activity observed in moderately active stars, and spatial distribution of stellar…
We analyse the phase-space structure of simulated thick discs that are the result of a significant merger between a disc galaxy and a satellite. Our main goal is to establish what would be the characteristic imprints of a merger origin for…
We present a self-similar, steady-state model describing both a magnetized accretion disc and a magnetohydrodynamic jet. We focus on the role of a hot corona in such a structure. This corona enables the disc to launch various types of jets.…
Magnetic interactions between a planet and its environment are known to lead to aurorae and shocks in the solar system. The large number of close-in exoplanets that have been discovered so far triggered a renewed interest in understanding…
Structure of a quasi-stationary stellar cluster is modelled assuming that it is embedded in the gravitational field of a super-massive black hole. Gradual orbital decay of stellar trajectories is caused by the dissipative interaction with…
The early pre-main sequence phase during which they are still likely surrounded by an accretion disk represents a puzzling stage of the rotational evolution of solar-mass stars. While they are still accreting and contracting they do not…