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[..] The change in the magnetic configuration due to the increase/decrease of electric current for different force-free models (potential, linear and nonlinear force-free fields) has never been studied in detail before. Here we focus…

Solar and Stellar Astrophysics · Physics 2015-05-28 S. Regnier

Solar prominences are magnetic structures incarcerating cool and dense gas in an otherwise hot solar corona. Prominences can be categorized as quiescent and active. Their origin and the presence of cool gas (~$10^4$K) within the hot…

Solar and Stellar Astrophysics · Physics 2023-04-03 Swati Routh , Snehanshu Saha , Atul Bhat , M. N. Sundar

We have studied three Interplanetary Coronal Mass Ejections (ICMEs) having clear signatures of magnetic cloud (MC) arrival at 1 AU and their associated solar sources during 2011 to 2013. Comparing the axial magnetic field strength (B0) of…

Solar and Stellar Astrophysics · Physics 2019-01-30 Ranadeep Sarkar , Nandita Srivastava

Using Particle-In-Cell simulations i.e. in the kinetic plasma description the discovery of a new mechanism of parallel electric field generation was recently reported. Here we show that the electric field generation parallel to the uniform…

Astrophysics · Physics 2008-06-10 David Tsiklauri

We investigate the occurrence of a CME-driven coronal dimming using unique high resolution spectral images of the corona from the Hinode spacecraft. Over the course of the dimming event we observe the dynamic increase of non-thermal line…

Astrophysics · Physics 2011-02-11 Scott W. McIntosh

We present a model of magnetohydrodynamic (MHD) turbulence in the extended solar corona that contains the effects of collisionless dissipation and anisotropic particle heating. Measurements made by UVCS/SOHO have revived interest in the…

Astrophysics · Physics 2009-11-07 S. R. Cranmer , A. A. van Ballegooijen

The high-speed solar wind is typically the simplest and least stochastic type of large-scale plasma flow in the heliosphere. For much of the solar cycle, it is connected magnetically to large polar coronal holes on the Sun's surface.…

Solar and Stellar Astrophysics · Physics 2020-12-22 Steven R. Cranmer

M dwarf's atmosphere is expected to be highly magnetized. The magnetic energy can be responsible for heating the stellar chromosphere and corona, and driving the stellar wind. The nonlinear propagation of Alfv\'en wave is the promising…

Solar and Stellar Astrophysics · Physics 2021-09-29 Takahito Sakaue , Kazunari Shibata

We study the evolutionary conditions for Kelvin-Helmholtz (KH) instability in a H-alpha solar surge observed in NOAA AR 8227 on 1998 May 30. The jet with speeds in the range of 45-50 km/s, width of 7 Mm, and electron number density of 3.83…

Solar and Stellar Astrophysics · Physics 2016-01-20 I. Zhelyazkov , T. V. Zaqarashvili , R. Chandra , A. K. Srivastava , T. Mishonov

Recent observations have demonstrated the capability of mapping the solar coronal magnetic field using the technique of coronal seismology based on the ubiquitous propagating Alfvenic/kink waves through imaging spectroscopy. We established…

Solar and Stellar Astrophysics · Physics 2024-11-14 Yuhang Gao , Hui Tian , Tom Van Doorsselaere , Zihao Yang , Mingzhe Guo , Konstantinos Karampelas

We have measured the widths of spectral lines from a polar coronal hole using the Extreme Ultraviolet Imaging Spectrometer onboard Hinode. Polar coronal holes are regions of open magnetic field and the source of the fast solar wind. We find…

Solar and Stellar Astrophysics · Physics 2015-06-04 Michael Hahn , Enrico Landi , Daniel Wolf Savin

Alfv\'enic waves are known to be prevalent throughout the corona and solar wind. Determining the Poynting flux supplied by the waves is required for constraining their role in plasma heating and acceleration, as well as providing a…

Solar and Stellar Astrophysics · Physics 2025-01-24 Richard J. Morton , Micah J. Weberg , N. Balodhi , James A. McLaughlin

The highly-filamented nature of the coronal plasma significantly influences dynamic processes in the corona such as magnetohydrodynamic waves and oscillations. Fast magnetoacoustic waves, guided by coronal plasma non-uniformities, exhibit…

Solar and Stellar Astrophysics · Physics 2023-11-27 Dmitrii Y. Kolotkov , Valery M. Nakariakov , Maximilien Cloesen

Observations reveal a correspondence between chromospheric type II spicules and bright upwardly moving fronts in the corona observed in the EUV band. However, theoretical considerations suggest that these flows are unlikely to be the main…

Solar and Stellar Astrophysics · Physics 2014-09-05 A. Petralia , F. Reale , S. Orlando , J. A. Klimchuk

Using the quantum Markovian master equation, we show that convection in the stellar photosphere generates plasma waves by an irreversible process akin to Zeldovich superradiance and sonic booms. In the Sun, this mechanism is most efficient…

Solar and Stellar Astrophysics · Physics 2022-03-08 Robert Alicki , Alejandro Jenkins

The thermodynamics of interplanetary coronal mass ejections (ICMEs) is often described using a polytropic process. Estimating the polytopic index ($\gamma$) allows us to quantify the expansion or compression of the ICME plasma arising from…

Solar and Stellar Astrophysics · Physics 2025-07-24 Debesh Bhattacharjee , Saikat Majumder , Prasad Subramanian

The Alfv\'en surface -- where the solar wind exceeds the local Alfv\'en speed as it expands into interplanetary space -- is now routinely probed by NASA's Parker Solar Probe (PSP) in the near-Sun environment. The size of the Alfv\'en…

Solar and Stellar Astrophysics · Physics 2025-10-29 Adam J. Finley

Stellar coronae are believed to be the main birthplace of various stellar magnetic activities. However, the structures and properties of stellar coronae remain poorly understood. Using the Space Weather Modelling Framework with the…

Plasma turbulence cascading from MHD to kinetic scales in the heliospheric plasma is believed to play a key role in coronal heating and fast solar wind acceleration, but the properties of the turbulence remain poorly constrained by…

Solar and Stellar Astrophysics · Physics 2026-02-03 Eduard P. Kontar , A. Gordon Emslie , Daniel L. Clarkson , Alexander Pitna
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