Dust formation in winds of long-period variables IV. Atmospheric dynamics and mass loss

Author(s)
Susanne Höfner, Ernst Dorfi
Abstract

We have calculated radiation-hydrodynamical models of the atmosphere and circumstellar dust shell of C-rich long-period variables which include a detailed description of the dust formation process. We discuss the time-dependent behaviour of the circumstellar envelope (e.g. multiperiodicity) and its relevance for observational properties like near-IR light curves and investigate the time-averaged mass loss characteristics of a sample of models satisfying radius-luminosity-mass and period-luminosity relations. The results can be summarized as follows: The dependence of the mass loss rate on stellar parameters predicts a strong increase of mass loss as stars evolve along the AGB. The models presented agree reasonably well with mean mass loss-period relations deduced from observations of Mira stars and the observed scatter of mass loss rates for a given period can be understood in terms of pulsation amplitude or non-linearities of the wind mechanism. The wind velocities show a good correlation with the quantity (?d/?g) L*/M* which characterizes the strength of radiation pressure on dust relative to gravitation.

Organisation(s)
Department of Astrophysics
External organisation(s)
Uppsala University
Journal
Astronomy & Astrophysics
Volume
319
Pages
648-654
No. of pages
7
ISSN
0004-6361
Publication date
1997
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/08a0cb6f-eada-4bc0-bc54-a0ca70a618d3