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Related papers: Red Giant Winds Driven by Alfv\'en Waves with Magn…

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We present results of 3D numerical simulations of magnetically confined, radiatively driven stellar winds of massive stars, conducted using the astrophysical MHD code Pluto, with a focus on understanding the rotational variability of radio…

Solar and Stellar Astrophysics · Physics 2017-12-01 Simon Daley-Yates , Ian Stevens

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

Spectra of the He I 10830 Angstrom line were obtained with NIRSPEC on the Keck 2 telescope for metal-deficient field giant stars. This line is ubiquitous in stars with T_eff greater than 4500K and M_V fainter than -1.5. Fast outflows are…

Solar and Stellar Astrophysics · Physics 2014-11-20 A. K. Dupree , G. H. Smith , J. Strader

The solar wind upstream of Mars's bow shock can be described in terms of Alfv\'enic turbulence, with an incompressible energy cascade rate of $10^{-17}$ J m$^{-3}$ s$^{-1}$ at magnetohydrodynamics (MHD) scales. The solar wind has more…

Solar and Stellar Astrophysics · Physics 2024-06-26 Norberto Romanelli , Christopher M. Fowler , Gina A. DiBraccio , Jared R. Espley , Jasper S. Halekas

The basic mechanisms responsible for producing winds from cool, late-type stars are still largely unknown. We take inspiration from recent progress in understanding solar wind acceleration to develop a physically motivated model of the…

Solar and Stellar Astrophysics · Physics 2015-05-30 Steven R. Cranmer , Steven H. Saar

Most numerical investigations on the role of magnetic fields in turbulent molecular clouds (MCs) are based on ideal magneto-hydrodynamics (MHD). However, MCs are weakly ionized, so that the time scale required for the magnetic field to…

Astrophysics · Physics 2009-11-13 Pak Shing Li , Christopher F. McKee , Richard I. Klein , Robert T. Fisher

Alfv\'en waves are primal and pervasive in space plasmas and significantly contributes to microscale fluctuations in the solar wind and some heliospheric processes. Here, we demonstrate the first observable distinct feature of Alfv\'en wave…

Space Physics · Physics 2018-10-16 Anil N. Raghav , Ankita Kule

The cumulative effect of the magnetized stellar winds on exoplanets dominates over other forms of star-planet interactions. When combined with photoevaporation, these winds will lead to atmospheric erosion. This is directly connected with…

Solar and Stellar Astrophysics · Physics 2021-11-19 Judy J. Chebly , Julián D. Alvarado-Gómez , Katja Poppenhaeger

The M dwarf star GJ 436 hosts a warm-Neptune that is losing substantial amount of atmosphere, which is then shaped by the interactions with the wind of the host star. The stellar wind is formed by particles and magnetic fields that shape…

Solar and Stellar Astrophysics · Physics 2023-10-18 A. A. Vidotto , V. Bourrier , R. Fares , S. Bellotti , J. F. Donati , P. Petit , G. A. J. Hussain , J. Morin

We show that an alpha effect is driven by the cosmic ray Bell instability exciting left-right asymmetric turbulence. Alfven waves of a preferred polarization have maximally helical motion, because the transverse motion of each mode is…

High Energy Astrophysical Phenomena · Physics 2012-06-21 Igor Rogachevskii , Nathan Kleeorin , Axel Brandenburg , David Eichler

We present a brief overview of the theory of stellar winds with a strong emphasis on the radiation-driven outflows from massive stars. The resulting implications for the evolution and fate of massive stars are also discussed. Furthermore,…

Solar and Stellar Astrophysics · Physics 2015-06-03 Jorick S. Vink

The generation of magnetohydrodynamic (MHD) waves and their instabilities are studied in galactic gaseous rotating plasmas with the effects of the magnetic field, the self gravity, the diffusion-convection of cosmic rays as well as the gas…

Plasma Physics · Physics 2022-11-07 Jyoti Turi , A. P. Misra

We present new wind models for {\tau} Bo\"otis ({\tau} Boo), a hot-Jupiter-host-star whose observable magnetic cycles makes it a uniquely useful target for our goal of monitoring the temporal variability of stellar winds and their…

Solar and Stellar Astrophysics · Physics 2016-11-15 B. A. Nicholson , A. A. Vidotto , M. Mengel , L. Brookshaw , B. Carter , P. Petit , S. C. Marsden , S. V. Jeffers , R. Fares , the BCool Collaboration

We study the interaction between the atmospheres of Venus-like, non-magnetized exoplanets orbiting an M-dwarf star, and the stellar wind using a multi-species Magnetohydrodynaic (MHD) model. We focus our investigation on the effect of…

Earth and Planetary Astrophysics · Physics 2015-06-11 O. Cohen , Y. Ma , J. J. Drake , A. Glocer , C. Garraffo , J. M. Bell , T. I. Gombosi

Galactic-scale winds are a generic feature of massive galaxies with high star formation rates across a broad range of redshifts. Despite their importance, a detailed physical understanding of what drives these mass-loaded global flows has…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Munier Salem , Greg L. Bryan

We present analytical solutions for winds from galaxies with NFW dark matter halo. We consider winds driven by energy and mass injection from multiple supernovae, as well as momentum injection due to radiation from a central black hole. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Mahavir Sharma , Biman B. Nath

Photospheric radiation momentum is efficiently transferred by absorption through metal lines to the gaseous matter in the atmospheres of massive stars, sustaining strong winds and mass loss rates. Not only is this critical for the evolution…

Astrophysics · Physics 2007-05-23 Fabio Bresolin , Rolf-Peter Kudritzki

We present a numerical Magnetohydrodynamic (MHD) study of the dependence of stellar mass and angular momentum- loss rates on the orbital distance to close-in giant planets. We find that the mass loss rate drops by a factor of…

Solar and Stellar Astrophysics · Physics 2015-05-20 O. Cohen , J. J Drake , V. L. Kashyap , I. V. Sokolov , T. I. Gombosi

Stellar winds from active solar type stars can play a crucial role in removal of stellar angular momentum and erosion of planetary atmospheres. However, major wind properties except for mass loss rates cannot be directly derived from…

Solar and Stellar Astrophysics · Physics 2016-02-17 Vladimir S. Airapetian , Arcadi V. Usmanov

We investigate non-ideal magnetohydrodynamical (MHD) effects in the chromosphere on the solar wind by performing MHD simulations for Alfv\'en-wave driven winds with explicitly including Ohmic and ambipolar diffusion. We find that MHD waves…

Solar and Stellar Astrophysics · Physics 2024-05-09 Masato Matsuoka , Takeru K. Suzuki , Takato Tokuno , Kensuke Kakiuchi