Related papers: Stellar Winds
Due to their short lifetimes but their enormous energy release in all stages of their lives massive stars are the major engines for the comic matter circuit. They affect not only their close environment but are also responsible to drive…
About ten percent of all OB stars show strong, large-scale surface magnetic fields. The interaction of the magnetic field and the wind is believed to be the cause for the X-ray emission shown by these objects. We therefore run numerical…
Magnetic fields are important at every scale in the star formation process: from the dynamics of the ISM in galaxies, to the collapse of turbulent molecular clouds to form stars and in the fragmentation of individual star forming cores. The…
Star formation is a complex multi-scale phenomenon that is of significant importance for astrophysics in general. Stars and star formation are key pillars in observational astronomy from local star forming regions in the Milky Way up to…
Spiral galaxies host dynamically important magnetic fields which can affect gas flows in the disks and halos. Total magnetic fields in spiral galaxies are strongest (up to 30 \muG) in the spiral arms where they are mostly turbulent or…
We solve the time-dependent dynamics of axisymmetric, general relativistic MHD winds from rotating neutron stars. The mass loss rate is obtained self consistently as a solution of the MHD equations, subject to a finite thermal pressure at…
Current burning issues in stellar physics, for both hot and cool stars, concern their magnetism. In hot stars, stable magnetic fields of fossil origin impact their stellar structure and circumstellar environment, with a likely major role in…
Initial results are presented from 3D MHD modelling of stellar-wind bubbles around O stars moving supersonically through the ISM. We describe algorithm updates that enable high-resolution 3D MHD simulations at reasonable computational cost.…
The evolution of star clusters is determined by several internal and external processes. Here we focus on two dominant internal effects, namely energy exchange between stars through close encounters (two-body relaxation) and mass-loss of…
Stellar spin is one of the fundamental quantities that characterize a star itself and its planetary system. Nevertheless, stellar spin-down mechanisms in protostellar and pre-main-sequence stellar phases have been a long-standing problem in…
Star formation is thought to be triggered by gravitational collapse of the dense cores of molecular clouds. Angular momentum conservation during the collapse results in the progressive increase of the centrifugal force, which eventually…
Pulsations driven by partial ionization of hydrogen in the envelope are often considered important for driving winds from red supergiants (RSGs). In particular, it has been suggested by some authors that the pulsation growth rate in a RSG…
Most of a star's mass is bound in a hydrostatic equilibrium in which pressure balances gravity. But if at some near-surface layer additional outward forces overcome gravity, this can transition to a supersonic, outflowing wind, with the…
Stars between about 4 and 25 solar masses spend a significant fraction of their post-main sequence lifetime as red supergiants (RSGs) and lose material via stellar winds during this period. For RSGs more massive than 10 solar masses, this…
We examine the effect of momentum-driven OB-star stellar winds on a parameter space of simulated turbulent Giant Molecular Clouds using SPH hydrodynamical simulations. By comparison with identical simulations in which ionizing radiation was…
The extent to which a magnetosphere protects its planetary atmosphere from stellar wind ablation depends upon how well it prevents energy and momentum exchange with the atmosphere and how well it traps otherwise escaping plasma. We focus on…
Stellar winds are a major source of uncertainty in understanding the life and deaths of massive stars. Across studies in the field, prescriptions for stellar winds differ substantially in both their physical assumptions and implementation,…
A review of recent observations of the kinematics of six objects that represent the broad range of phenomena called planetary nebulae (PNe) is presented. It is demonstrated that Hubble-type outflows are predominant, consequently it is…
The long-term evolution of stellar orbits bound to a massive centre is studied in order to understand the cores of star clusters in central regions of galaxies. Stellar trajectories undergo tiny perturbation, the origin of which is twofold:…
The modelling of massive star evolution is a complex task, and is very sensitive to the way physical processes (such as convection, rotation, mass loss, etc.) are included in stellar evolution code. Moreover, the very high observed fraction…