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Related papers: Modeling Time-Variable Elemental Abundances in Cor…

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Context. The relative importance of AC and DC heating in maintaining the temperature of the corona is not well constrained. Aims. Investigate the effects of the characteristic time scales of photospheric driving on the injection and…

Solar and Stellar Astrophysics · Physics 2020-11-11 Thomas Howson , Ineke De Moortel , Lianne Fyfe

In solar coronal loops, thermal non-equilibrium (TNE) is a phenomenon that can occur when the heating is both highly-stratified and quasi-constant. Unambiguous observational identification of TNE would thus permit to strongly constrain…

Solar and Stellar Astrophysics · Physics 2017-02-08 Clara Froment , Frédéric Auchère , Guillaume Aulanier , Zoran Mikić , Karine Bocchialini , Eric Buchlin , Jacques Solomon

We present a study of the spatial and spectral evolution of the loop-top (LT) sources in a sample of 6 flares near the solar limb observed by {\it RHESSI}. A distinct coronal source, which we identify as the LT source, was seen in each of…

Astrophysics · Physics 2009-11-13 Yan Wei Jiang , Siming Liu , Wei Liu , Vahe Petrosian

This work investigates the decayless kink oscillations of solar coronal loops and examines possible changes in their behaviour in active regions (ARs) before powerful solar flares (M- and X-class) and in the absence of powerful flares. To…

Solar and Stellar Astrophysics · Physics 2025-11-10 A. B. Nechaeva , I. V. Zimovets , I. N. Sharykin , S. A. Anfinogentov

We revisit in more detail a model for element abundance fractionation in the solar chromosphere, that gives rise to the "FIP Effect" in the solar corona and wind. Elements with first ionization potential below about 10 eV, i.e. those that…

Solar and Stellar Astrophysics · Physics 2014-11-18 J. Martin Laming

Context. Photospheric motions shuffle the footpoints of the strong axial magnetic field that threads coronal loops giving rise to turbulent nonlinear dynamics characterized by the continuous formation and dissipation of field-aligned…

Solar and Stellar Astrophysics · Physics 2012-08-14 R. B. Dahlburg , G. Einaudi , A. F. Rappazzo , M. Velli

Spatially unresolved observations show that the cooling phase in solar flares can be much longer than theoretical models predict. It has not yet been determined whether this is also the case for different subregions within the flare…

Solar and Stellar Astrophysics · Physics 2024-06-21 Malte Bröse , Alexander Warmuth , Taro Sakao , Yang Su

During the last few decades, the most widely favored models for coronal heating have involved the in situ dissipation of energy, with footpoint shuffling giving rise to multiple current sheets (the "nanoflare" model) or to Alfv{\'e}n waves…

Solar and Stellar Astrophysics · Physics 2022-10-04 Y. -M. Wang

Thermal non-equilibrium (TNE) is a phenomenon that can occur in solar coronal loops when the heating is quasi-constant and highly-stratified. Under such heating conditions, coronal loops undergo cycles of evaporation and condensation. The…

Solar and Stellar Astrophysics · Physics 2019-12-25 C. Froment , P. Antolin , V. M. J. Henriques , P. Kohutova , L. H. M. Rouppe van der Voort

We have analyzed H-alpha intensity images obtained at a 1 minute cadence with the Global Oscillation Network Group (GONG) system to investigate the properties of oscillations in the 0-8 mHz frequency band at the location and time of strong…

Solar and Stellar Astrophysics · Physics 2018-03-08 Teresa Monsue , Frank Hill , Keivan G. Stassun

A complete understanding of solar radio bursts requires developing numerical techniques which can connect large-scale activities with kinetic plasma processes. As a starting point, this study presents a numerical scheme combining three…

Solar and Stellar Astrophysics · Physics 2021-03-10 M. Yousefzadeh , H. Ning , Y. Chen

Recent observations in extreme-ultraviolet (EUV) wavelengths reveal an EUV late phase in some solar flares that is characterized by a second peak in warm coronal emissions ($\sim3$~MK) several tens of minutes to a few hours after the soft…

Solar and Stellar Astrophysics · Physics 2018-05-02 Yu Dai , Mingde Ding

We present here one of the first high resolution spectroscopic observations of coronal rain, performed with the CRISP instrument at the Swedish Solar Telescope. This work constitutes the first attempt to assess the importance of coronal…

Solar and Stellar Astrophysics · Physics 2015-06-03 Patrick Antolin , Luc Rouppe van der Voort

We construct magnetostatic models of coronal loops in which the thermodynamics of the loop is fully consistent with the shape and geometry of the loop. This is achieved by treating the loop as a thin, compact, magnetic fibril that is a…

Solar and Stellar Astrophysics · Physics 2015-06-16 Bradley W. Hindman , Rekha Jain

Coronal waves, significant solar phenomena, act as diagnostic tools for scientists studying solar atmosphere properties. Here, we present a novel observation detailing how a coronal wave event, associated with an X5.0 class flare,…

We investigate numerically the time evolution of velocity and magnetic field fluctuations in a coronal loop, focusing on the dynamics due to both phase mixing and turbulent cascade. The intensity, doppler velocity and non-thermal broadening…

The origin of the slow solar wind is not well understood, unlike the fast solar wind which originates from coronal holes. In-situ elemental abundances of the slow solar wind suggest that it originates from initially closed field lines that…

Solar and Stellar Astrophysics · Physics 2025-02-28 Alexandros Koukras , Daniel W. Savin , Michael Hahn

Slow magnetosonic waves associated with flares were observed in coronal loops by SOHO/SUMER, SDO/AIA in various EUV bandpasses, and other instruments. The excitation and damping of slow magnetosonic waves provides information on the…

Solar and Stellar Astrophysics · Physics 2022-02-23 Leon Ofman , Tongjiang Wang

Magnetic reconnection in the corona results in contracting flare loops, releasing energy into plasma heating and shocks. The hydrodynamic shocks so produced drive thermal conduction fronts (TCFs) which transport energy into the chromosphere…

Solar and Stellar Astrophysics · Physics 2015-06-22 Sean Brannon , Dana Longcope

In strong stellar and solar flares flare loops typically appear during the decay phase, providing an additional contribution to the flare emission and, possibly, obscuring the flare emission. Super-flares, common in active, cool stars,…

Solar and Stellar Astrophysics · Physics 2024-08-06 Kamil Bicz , Robert Falewicz , Petr Heinzel , Małgorzata Pietras , Paweł Preś