A comparison of the reduced and approximate systems for the time dependent computation of the polar wind and multiconstituent stellar winds

1992 ◽  
Vol 97 (A2) ◽  
pp. 1289
Author(s):  
G. L. Browning ◽  
T. E. Holzer
Keyword(s):  
Time Dependent ◽  
Stellar Winds ◽  
Polar Wind

scholarly journals Dust Driven Winds from Pulsating Stars

1993 ◽  
Vol 137 ◽  
pp. 572-574 ◽  
Author(s):  
E.A. Dorfi ◽  
M.U. Feuchtinger ◽  
S. Höfner
Keyword(s):  
The Self ◽  
Time Dependent ◽  
Full Description ◽  
Stellar Winds ◽  
Dust Formation ◽  
Radiation Hydrodynamics ◽  
Simple Description ◽  
Pulsating Stars ◽  
Self Consistent ◽  
Different Parts

The cool extended atmospheres of late type giants are sites where dust formation takes place. Radiation pressure on the dust grains is an important force for driving the slow but massive winds observed in such objects. Existing calculations of dust driven stellar winds (e.g. Bowen 1988, Fleischer et al. 1991) suffer from the fact that they include approximations at various levels for different parts of the problem like the hydrodynamics or the dust formation. Furthermore they do not include time-dependent radiative transfer.In order to overcome these insufficiencies we plan to calculate self-consistent models of dust driven winds with a full description of both the radiation hydrodynamics and the time-dependent dust formation. As a first step, however, we concentrate our investigations on the self-consistent description of the radiation hydrodynamics adopting only a simple description of the dust opacities.

scholarly journals A time-dependent theoretical model of the polar wind: Preliminary results

1985 ◽  
Vol 12 (4) ◽  
pp. 167-170 ◽  
Author(s):  
T. I. Gombosi ◽  
T. E. Cravens ◽  
A. F. Nagy
Keyword(s):  
Theoretical Model ◽  
Time Dependent ◽  
Polar Wind ◽  
Preliminary Results

scholarly journals The Influences of Stellar Activity on Planetary Atmospheres

2016 ◽  
Vol 12 (S328) ◽  
pp. 168-179
Author(s):  
Colin P. Johnstone
Keyword(s):  
Mass Loss ◽  
Planetary Atmospheres ◽  
Time Dependent ◽  
Stellar Winds ◽  
Additional Mass ◽  
Stellar Activity ◽  
X Ray

AbstractOn evolutionary timescales, the atmospheres of planets evolve due to interactions with the planet's surface and with the planet's host star. Stellar X-ray and EUV (=’XUV’) radiation is absorbed high in the atmosphere, driving photochemistry, heating the gas, and causing atmospheric expansion and mass loss. Atmospheres can interact strongly with the stellar winds, leading to additional mass loss. In this review, I summarise some of the ways in which stellar output can influence the atmospheres of planets. I will discuss the importance of simultaneously understanding the evolution of the star's output and the time dependent properties of the planet's atmosphere.

scholarly journals Clumped stellar winds in supergiant high-mass X-ray binaries

2012 ◽  
Vol 8 (S290) ◽  
pp. 287-288 ◽  
Author(s):  
L. M. Oskinova ◽  
A. Feldmeier ◽  
P. Kretschmar
Keyword(s):  
Stellar Wind ◽  
Compact Object ◽  
Time Dependent ◽  
High Mass ◽  
Stellar Winds ◽  
Degree Of Ionization ◽  
X Ray ◽  
Wind Theory ◽  
Supergiant Star ◽  
X Ray Binaries

AbstractThe clumping of massive star winds is an established paradigm, which is confirmed by multiple lines of evidence and is supported by stellar wind theory. We use the results from time-dependent hydrodynamical models of the instability in the line-driven wind of a massive supergiant star to derive the time-dependent accretion rate on to a compact object in the Bondi-Hoyle-Lyttleton approximation. The strong density and velocity fluctuations in the wind result in strong variability of the synthetic X-ray light curves. Photoionization of inhomogeneous winds is different from the photoinization of smooth winds. The degree of ionization is affected by the wind clumping. The wind clumping must also be taken into account when comparing the observed and model spectra of the photoionized stellar wind.

scholarly journals Observations of deep-seated structure in the stellar winds of OB stars

1995 ◽  
Vol 10 ◽  
pp. 344-348
Author(s):  
R. K. Prinja
Keyword(s):  
Time Dependent ◽  
Stellar Winds ◽  
Line Profiles ◽  
Resolution Time ◽  
Hot Stars ◽  
Time Resolved ◽  
Ob Stars ◽  
Spectroscopic Monitoring ◽  
Wind Structure ◽  
Nonradial Pulsation

High-resolution, time-resolved spectroscopy in both optical and UV wavebands has shown that the outer layers of luminous OB stars vary on time scales of hours-days. Spectroscopic monitoring with the IUE satellite provides evidence that the stellar winds of luminous, hot stars are not smooth and steady, but are frequently disrupted by the presence of time-dependent structures. In addition, variability is often present in optical photospheric line profiles; these variations are likely due to the influence of photospheric velocity fields, especially those from one or more modes of nonradial pulsation (NRP). The process (or processes) responsible for the formation of time-dependent wind structure is (are) not known. Issues concerning potential connections between NRPs, variations at the base of the outflow, and the development of wind structure pose some of the greatest challenges to our understanding of mass-loss via radiatively driven stellar winds.

Sign in / Sign up

Export Citation Format

Share Document