Radiation-driven wind theory: The influence of turbulence

2008 ◽  
pp. 414-416
Author(s):  
Daniel Schaerer ◽  
Werner Schmutz
Keyword(s):  
Wind Theory

scholarly journals Theoretical Light Curves of Recurrent Novae

1993 ◽  
Vol 155 ◽  
pp. 408-408
Author(s):  
M. Kato
Keyword(s):  
Decay Time ◽  
Time Scale ◽  
Light Curves ◽  
Decay Phase ◽  
Wind Theory

Theoretical light curves for the decay phase of recurrent novae are obtained using optically thick wind theory. With the OPAL opacity tables the decay time scale is drastically shortened.

scholarly journals Influence of the Stellar Winds on the Evolution of the Planetary Nebula Nuclei

1993 ◽  
Vol 155 ◽  
pp. 483-483
Author(s):  
S.K. Górny
Keyword(s):  
Mass Loss ◽  
Planetary Nebula ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Stellar Winds ◽  
Hydrogen Burning ◽  
Wind Theory ◽  
Homogeneous Models ◽  
Image Position ◽  
Zero Points

A grid of homogeneous models of evolution of hydrogen burning planetary nebulae nuclei, assuming different stellar winds and the zero points for the post-AGB evolution, have been constructed from original Schönberners tracks. Following a simplified line-driven wind theory the mass loss rate has been adopted to be

scholarly journals On the Evolution of the Nova-like Variable AE Aquarii

2004 ◽  
Vol 190 ◽  
pp. 300-306
Author(s):  
P. J. Meintjes
Keyword(s):  
Mass Transfer ◽  
Orbital Period ◽  
White Dwarf ◽  
Time Scale ◽  
Critical Mass ◽  
Current Phase ◽  
Thermal Activity ◽  
Secondary Star ◽  
Wind Theory ◽  
Mass Ejection

AbstractIt is shown here that the peculiar properties of AE Aqr can can be accounted for if the mass transfer from an evolved 0.7M⊙ secondary K4-5 star (qi ≈ 0.8, i.e. < 1) initiated when the orbital period of the binary was Porb,i ≈ 8.5 hours and the white dwarf period P*,i ≈ 1 hour. This resulted in a significant amount of orbital angular momentum being accreted by the white dwarf in an initial discless spin-up phase towards P* ≈ 0.1 Porb,i. This destabilized the mass transfer, resulting in a run-away mass transfer from the secondary that lasted for approximately 104 years, with the orbital period evolving to Porb ≈ 11 hours until a critical mass ratio of qcrit = 0.73 had been reached. In this phase the mass transfer from the secondary occurred at a rapid rate of approximately Ṁ2 ≈ 1020 g s-1, resulting in an accretion disc which spun-up the white dwarf to a period of approximately P* ≈ 33 s. For all q ≤ qcrit = 0.73 the mass transfer proceeded on the thermal time scale of the secondary star, i.e. at a much slower rate, resulting in the binary converging and forcing AE Aqr into the propeller phase. Applying stellar wind theory, this allow an estimate of the polar magnetic field of the secondary star, which is of the order of B° ≈ (1600 – 2000) G. It has been shown here that the duration of mass transfer phase q = qcrit → 0.67 (now) lasted for approximately tṀ2 ~ 107 years, similar to the spin-down time scale of the white dwarf, tsd = P*/P* ≈ 107 years. The propeller ejection of matter in the current phase results in the dissipation of mhd power of Lmhd ≈ 1034 erg s-1, probably channeled into mass ejection and non-thermal activity. This explains the non-thermal outbursts that are observed in radio wavelengths, and occasionally also in TeV energies, from AE Aqr.

scholarly journals Wolf-Rayet Stellar Wind Theory

1991 ◽  
Vol 143 ◽  
pp. 289-308
Author(s):  
J. P. Cassinelli
Keyword(s):  
Magnetic Fields ◽  
Stellar Wind ◽  
Equatorial Zone ◽  
Radio Flux ◽  
Polar Wind ◽  
Radiative Processes ◽  
Rotator Model ◽  
Show Evidence ◽  
Wind Theory

Two possible solutions to the Wolf-Rayet wind momentum problem are discussed: purely radiation driven wind theory, with multi-line effects, and Luminous Magnetic Rotator theory. Several recently developed radiative processes for enhancing M or v∞ are described, and it is concluded that only the winds of rather hot luminous Wolf-Rayet stars could possibly be driven by radiation. These stars should show evidence of acceleration at large radial distances. For the rapid rotators, it is possible to drive a dense equatorial outflow. Limits are discussed regarding the needed surface magnetic fields. With this model, the wind momentum problem is solved in a piece-wise fashion by having the large radio flux of Wolf-Rayet stars come from the equatorial zone and the broad P Cygni lines, arising in the polar wind. The Luminous Magnetic Rotator model can also be tested through observation, primarily through spectropolarimetry.

scholarly journals No breakdown of the radiatively driven wind theory in low-metallicity environments★†

2015 ◽  
Vol 449 (2) ◽  
pp. 1545-1569 ◽  
Author(s):  
J.-C. Bouret ◽  
T. Lanz ◽  
D. J. Hillier ◽  
F. Martins ◽  
W. L. F. Marcolino ◽  
...  
Keyword(s):  
Wind Theory ◽  
Low Metallicity
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