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Related papers: Dust in AGB stars: transparent or opaque?

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The properties and the evolution of asymptotic giant branch (AGB) stars are strongly influenced by their mass loss through a stellar wind. This is believed to be caused by radiation pressure due to the absorption and scattering of the…

Solar and Stellar Astrophysics · Physics 2023-05-03 Kjell Eriksson , Susanne Höfner , Bernhard Aringer

Winds of asymptotic giant branch (AGB) stars are commonly assumed to be driven by radiative acceleration of dust grains. For M-type AGB stars, the nature of the wind-driving dust species has been a matter of intense debate. A proposed…

Solar and Stellar Astrophysics · Physics 2017-07-19 Erik Aronson , Sara Bladh , Susanne Höfner

The slow, dense winds observed in evolved asymptotic giant branch (AGB) stars are usually attributed to a combination of dust formation in the dynamical inner atmosphere and momentum transfer from stellar photons interacting with the newly…

Solar and Stellar Astrophysics · Physics 2019-06-26 Sara Bladh

Dust grains forming in the extended atmospheres of AGB stars are critical for the heavy mass loss of these cool luminous giants, as they provide radiative acceleration for the stellar winds. Characteristic mid-IR spectral features indicate…

Solar and Stellar Astrophysics · Physics 2019-03-27 Susanne Höfner , Bernd Freytag

Wind-driving in asymptotic giant branch (AGB) stars is commonly attributed to a two-step process. First, matter in the stellar atmosphere is levitated by shock waves, induced by stellar pulsation, and second, this matter is accelerated by…

Solar and Stellar Astrophysics · Physics 2017-09-27 S. Liljegren , S. Höfner , K. Eriksson , W. Nowotny

We aim to constrain the dust mass and grain sizes in the interaction regions between the stellar winds and the ISM around asymptotic giant branch stars. By describing the dust in these regions, we aim to shed light on the role of low mass…

Astrophysics of Galaxies · Physics 2022-09-21 M. Maercker , T. Khouri , M. Mecina , E. De Beck

For amorphous carbon several laboratory extinction data are available, which show quite a wide range of differences due to the structural complexity of this material. We have calculated self-consistent dynamic models of circumstellar…

Astrophysics · Physics 2007-05-23 Anja C. Andersen , Rita Loidl , Susanne Hofner

The winds observed around AGB stars are generally attributed to radiation pressure on dust formed in the dynamical atmospheres of these long-period variables. The composition of wind-driving grains is affected by a feedback between their…

Solar and Stellar Astrophysics · Physics 2022-01-19 Susanne Höfner , Sara Bladh , Bernhard Aringer , Kjell Eriksson

We present three-component wind models for carbon rich pulsating AGB stars. In particular we study the effects of drift in models of long-period variables, meaning that the dust is allowed to move relative to the gas (drift models). In…

Astrophysics · Physics 2009-11-07 C. Sandin , S. Hoefner

The commonly accepted mechanism governing the formation of the nascent wind in oxygen-rich AGB stars combines an initial boost above the photosphere, given by shock waves resulting from stellar pulsations and convective cell granulation,…

Solar and Stellar Astrophysics · Physics 2023-08-07 P. Darriulat , D. T. Hoai , P. T. Nhung , P. N. Diep , N. B. Ngoc , T. T. Thai , P. Tuan-Anh

Mass loss is a crucial component in stellar evolution models, since it largely determines the rate of evolution at the later stages of a star's life. The dust-driven outflows from AGB stars are particularly important in this regard.…

Solar and Stellar Astrophysics · Physics 2017-10-16 Lars Mattsson , Paolo Ventura

We compare observations of AGB stars and predictions of the Elitzur & Ivezic (2001) steady-state radiatively driven dusty wind model. The model results are described by a set of similarity functions of a single independent variable, and…

Solar and Stellar Astrophysics · Physics 2015-05-18 Zeljko Ivezic , Moshe Elitzur

We present asymptotic giant branch (AGB) models of metallicity $Z=10^{-4}$ and $Z=3\times 10^{-4}$, with the aim of understanding how the gas enrichment and the dust production change in very metal-poor environments and to assess the…

Solar and Stellar Astrophysics · Physics 2019-05-08 F. Dell'Agli , R. Valiante , D. Kamath , P. Ventura , D. A. García-Hernández

Context: Stars evolving through the asymptotic giant branch (AGB) phase provide significant feedback to their host system, in form of both gas enriched in nuclear-burning products and dust formed in their winds, which they eject into the…

Solar and Stellar Astrophysics · Physics 2020-07-07 Paolo Ventura , Flavia Dell'Agli , Maria Lugaro , Donatella Romano , Marco Tailo , Andres Yague

The recent progress in high-spatial-resolution techniques, spanning wavelengths from the visual to the radio regime, is leading to new valuable insights into the complex dynamical atmospheres of Asymptotic Giant Branch (AGB) stars and their…

Solar and Stellar Astrophysics · Physics 2016-10-28 Susanne Höfner

High spatial resolution techniques have given valuable insights into the mass loss mechanism of AGB stars, which presumably involves a combination of atmospheric levitation by pulsation-induced shock waves and radiation pressure on dust.…

Solar and Stellar Astrophysics · Physics 2016-10-19 Susanne Höfner , Sara Bladh , Bernhard Aringer , Rajeev Ahuja

The intricate interplay of atmospheric shock waves and a complex, variable radiation field with non-equilibrium dust formation presents a considerable challenge to self-consistent modelling of atmospheres and winds of AGB stars.…

Astrophysics · Physics 2007-05-23 S. Hoefner

We examine the flow from asymptotic giant branch (AGB) stars when along a small solid angle the optical depth due to dust is very large. We consider two types of flows. In the first, small cool spots are formed on the surface of slowly…

Astrophysics · Physics 2009-10-31 Noam Soker

Molecules and dust produced by the atmospheres of cool evolved stars contribute to a significant amount of the total material found in the interstellar medium. To understand the mechanism behind the mass loss of these stars, it is of…

Solar and Stellar Astrophysics · Physics 2019-09-11 Gioia Rau , Keiichi Ohnaka , Markus Wittkowski , Vladimir Airapetian , Kenneth G. Carpenter

Radiative acceleration of newly-formed dust grains and transfer of momentum from the dust to the gas plays an important role for driving winds of AGB stars. Therefore a detailed description of the interaction of gas and dust is a…

Astrophysics · Physics 2009-11-07 C. Sandin , S. Hoefner