Related papers: On continuum driven winds from rotating stars
We have investigated the possibility that radiation pressure might trigger planetary nebula (PN) ejection during helium-shell flashes in asymptotic- giant-branch (AGB) stars. We find that the outward flux at the base of the hydrogen…
We present 2D MHD simulations of the radiatively driven outflow from a rotating hot star with a dipole magnetic field aligned with the star's rotation axis. We focus primarily on a model with moderately rapid rotation (half the critical…
The theory of radiation driven wind including stellar rotation is re-examined. After a suitable change of variables, a new equation for the mass loss rate is derived analytically. The solution of this equation remains within 1% confidence…
$\eta$ Carinae is an extraordinary massive star famous for its 19th century Great Eruption and the surrounding Homunculus nebula ejected in that event. The cause of this eruption has been the centre of a long-standing mystery. Recent…
We present a model for the steady state winds of super-Eddington systems. These radiatively driven winds are expected to be optically thick and clumpy as they arise from a porous atmosphere. The model is then used to derive the mass loss of…
The rotation axis of the Sun is misaligned from the mean angular momentum plane of the Solar system by about 6 degrees. This obliquity significantly exceeds the ~1-2 degree distribution of inclinations among the planetary orbits and…
Here, I review some recent works on magnetism of cool, main-sequence stars, their winds and potential impact on surrounding exoplanets. The winds of these stars are very tenuous and persist during their lifetime. Although carrying just a…
Rotation and mass loss are crucially interlinked properties of massive stars, strongly affecting their evolution and ultimate fate. Massive stars rotating near their breakup limit shed mass centrifugally, creating Be stars with…
The effects of the stellar rotation and the consequent azimuthal stellar wind flow in Parker's [9] hydrodynamic stellar wind model are discussed. Of special interest is the emergence of a whole new hydrodynamic physics via a new critical…
We suggest that the mass lost during the evolution of very massive stars may be dominated by optically thick, continuum-driven outbursts or explosions, instead of by steady line-driven winds. In order for a massive star to become a WR star,…
Extreme helium stars are very rare low-mass supergiants in a late stage of evolution. They are probably contracting to become white dwarfs following a violent phase of evolution which caused them to become hydrogen-deficient giants,…
We present a brief overview of the theory of stellar winds with a strong emphasis on the radiation-driven outflows from massive stars. The resulting implications for the evolution and fate of massive stars are also discussed. Furthermore,…
We present here new results of two-dimensional hydrodynamical simulations of the eruptive events of the 1840s (the great) and the 1890s (the minor) eruptions suffered by the massive star $\eta$ Car. The two bipolar nebulae commonly known as…
We present a model for steady state winds of systems with super-Eddington luminosities. These radiatively driven winds are expected to be optically thick and clumpy as they arise from an instability driven porous atmosphere. The model is…
We here present two-dimensional, time-dependent radiatively cooling hydrodynamical simulations of the large and little Homunculus nebulae around $\eta$ Carinae. We employ an alternative scenario to previous interacting stellar wind models…
Rotation in massive stars has been studied on the main sequence and during helium burning for decades, but only recently have realistic numerical simulations followed the transport of angular momentum that occurs during more advanced stages…
In this paper we explore the dynamics of ionization bounded planetary nebulae after the termination of the fast stellar wind. When the stellar wind becomes negligible, the hot, shocked bubble depressurizes and the thermal pressure of the…
We illustrate how rotation of the central star can give rise to latitudinal variations in the wind properties from the star. Interaction of these winds with the surrounding medium can produce asymmetrical planetary nebulae.
We study the dynamics of stellar wind bubbles around hydrogen-deficient stars using numerical simulations with time- and ion dependent cooling. We consider two types of hydrogen-deficient stars, massive WR stars, producing Ring Nebulae, and…
We compare the angular momentum extracted by a wind from a pre-main-sequence star to the torques arising from the interaction between the star and its Keplerian accretion disk. We find that the wind alone can counteract the spin-up torque…