The Porous Atmosphere of η Carinae

@article{Shaviv2000ThePA,
  title={The Porous Atmosphere of $\eta$ Carinae},
  author={Nir J. Shaviv},
  journal={The Astrophysical Journal Letters},
  year={2000},
  volume={532},
  pages={L137 - L140}
}
  • N. Shaviv
  • Published 9 February 2000
  • Physics
  • The Astrophysical Journal Letters
We analyze the wind generated by the great 20 yr-long super-Eddington outburst of η Carinae. We show that by using the classical stellar atmosphere and wind theory, it is impossible to construct a consistent wind model in which a sufficiently small amount of mass, like the one observed, is shed. One expects the super-Eddington luminosity to drive a thick wind with a mass-loss rate substantially higher than the observed one. The easiest way to resolve the inconsistency is if we alleviate the… 

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References

SHOWING 1-10 OF 17 REFERENCES

Variable and Nonspherical Stellar Winds in Luminous Hot Stars: IAU Colloquium 169

The winds of hot stars are generally understood to be driven by the absorption of momentum from the intense stellar radiation field by line transitions in the ultraviolet and farultraviolet regions

Photofluid instabilities of hot stellar envelopes

THE LUMINOUS BLUE VARIABLES: ASTROPHYSICAL GEYSERS

Some of the most luminous stars have sporadic, violent mass-loss events whose cuases are not understood. These evolved hot stars are called Luminous Blue Variables (LBV's), and their instability may

The Eddington Luminosity Limit for Multiphased Media

We consider the effective Eddington luminosity in a locally inhomogeneous medium by averaging out the coarse, small-scale behavior. We show that the ratio between the emitted flux and the average

Extremely luminous atmospheres

We present the effects that inhomogeneities have on radiating atmospheres. It is shown that nonuniformities in a medium induce a reduction of the effective opacity which subsequently increases the

Updated Opal Opacities

The reexamination of astrophysical opacities has eliminated gross discrepancies between a variety of observations and theoretical calculations; thus allowing for more detailed tests of stellar

Stellar winds driven by super-Eddington luminosities

On construit plus de 100 modeles de l'ecoulement externe stable et a symetrie spherique d'un gaz d'une etoile de 1,4 M ○. avec une enveloppe d'helium pur et une luminosite depassant parfois la limite

Eta carinae and its environment

▪ Abstract Eta Carinae (Eta) is one of the most remarkable of all well-studied stars and perhaps the most poorly understood. Observations with the Hubble Space Telescope and other modern instruments

Foundations of Radiation Hydrodynamics

Exposes the great foundation-stones of research on radiating flows in astrophysics. Upon them are built the walls of methodology (some understandably incomplete). Concentration is on fundamentals but

Optically thick winds and nova outbursts

Etude de la structure des enveloppes perdant de la masse et optiquement epaisses de naines blanches, en relation avec des explosions de novae