English
Related papers

Related papers: Magnetic field extrapolation in active region well…

200 papers

We investigate the footpoints of four erupted magnetic flux ropes (MFRs) that appear as sigmoidal hot channels prior to the eruptions in the Atmospheric Imaging Assembly high temperaure passbands. The simultaneous Helioseismic and Magnetic…

Solar and Stellar Astrophysics · Physics 2016-08-03 X. Cheng , M. D. Ding

Observations of the upper chromosphere shows an enormous amount of intricate fine structure. Much of this comes in the form of linear features which are most often assumed to be well aligned with the direction of the magnetic field in the…

Solar and Stellar Astrophysics · Physics 2017-10-23 Juan Martínez-Sykora , Bart De Pontieu , Mats Carlsson , Viggo Hansteen

We investigated the initiation and the evolution of an X7.1-class solar flare observed in solar active region NOAA 13842 on October 1, 2024, based on a data-constrained magnetohydrodynamic (MHD) simulation. The nonlinear force-free field…

Solar and Stellar Astrophysics · Physics 2025-08-12 Keitarou Matsumoto , Satoshi Inoue , Nian Liu , Keiji Hayashi , Ju Jing , Haimin Wang

We explore the empirical power-law relationship between X-ray luminosity (Lx) and total surface magnetic flux (Phi), established across solar magnetic elements, time- and disk-averaged emission from the Sun, older active stars, and…

An enhancement in high-frequency acoustic power is commonly observed in the solar photosphere and chromosphere surrounding magnetic active regions. We perform 3D linear forward wave modelling with a simple wavelet pulse acoustic source to…

Solar and Stellar Astrophysics · Physics 2015-06-23 Carlos Rijs , Hamed Moradi , Damien Przybylski , Paul S. Cally

Force-freeness of a solar magnetic field is a key to reconstructing invisible coronal magnetic structure of an emerging flux region on the Sun where active phenomena such as flares and coronal mass ejections frequently occur. We have…

Solar and Stellar Astrophysics · Physics 2015-06-23 Jihye Kang , Tetsuya Magara

We study the magnetic reconnection during a flare by investigating flare ribbon dynamics using observations and data-constrained magnetohydrodynamics (MHD) simulation. In particular, we estimate the reconnection flux and the reconnection…

Solar and Stellar Astrophysics · Physics 2025-05-19 Sushree S Nayak , Qiang Hu , Wen He , Sanjay Kumar , Ramit Bhattacharyya

Coronal magnetic fields evolve quasi statically over long time scales and dynamically over short time scales. As of now there exists no regular measurements of coronal magnetic fields, and therefore generating the coronal magnetic field…

Solar and Stellar Astrophysics · Physics 2023-12-20 P. Vemareddy , Jörn Warnecke , Ph. A. Bourdin

The observations of magnetic field variations as a signature of flaring activity is one of the main goal in solar physics. Some efforts in the past give apparently no unambiguous observations of changes. We observed that the scaling laws of…

Diagnosing solar flare conditions is essential for understanding coronal energy release. Using combined microwave and X-ray data, we reconstruct three-dimensional maps of the magnetic field and plasma parameters in the SOL2021-05-07 flare.…

Solar and Stellar Astrophysics · Physics 2026-03-06 Tatyana Kaltman , Sijie Yu , Gregory D. Fleishman , Daniel F. Ryan

During eruptive flares, vector magnetograms show increasing horizontal magnetic field and downward Lorentz force in the Sun's photosphere around the polarity-inversion line. Such behavior has often been associated with the implosion…

Solar and Stellar Astrophysics · Physics 2019-06-05 Krzysztof Barczynski , Guillaume Aulanier , Sophie Masson , Michael S. Wheatland

Radiative magnetohydrodynamic simulation includes sufficiently realistic physics to allow for the synthesis of remote sensing observables that can be quantitatively compared with observations. We analyze the largest flare in a simulation of…

Solar and Stellar Astrophysics · Physics 2023-06-28 Feng Chen , Matthias Rempel , Yuhong Fan

Studies of the three-dimensional (3D) structures of galactic magnetic fields are now entering a new era, with broadband, highly sensitive radio observations and new analysis methods. To reveal the magnetic field configuration from the…

Astrophysics of Galaxies · Physics 2023-03-07 Yuta Tashima , Takumi Ohmura , Mami Machida

We study flare processes in the lower solar atmosphere using observational data for a M1-class flare of June 12, 2014, obtained by New Solar Telescope (NST/BBSO) and Helioseismic Magnetic Imager (HMI/SDO). The main goal is to understand…

Solar and Stellar Astrophysics · Physics 2016-04-20 I. N. Sharykin , V. M. Sadykov , A. G. Kosovichev , S. Vargas-Dominguez , I. V. Zimovets

We introduce to the stellar physics community a method of modelling stellar coronae that can be considered to be an extension of the potential field. In this approach, the magnetic field is coupled to the background atmosphere. The model is…

Solar and Stellar Astrophysics · Physics 2015-12-23 David MacTaggart , Scott Gregory , Thomas Neukirch , Jean-Francois Donati

Identifying solar active regions (ARs), which consist of one or more pairs of magnetic patches with opposite polarities, is essential due to their significant role in dynamic solar atmospheric phenomena. In this study, we analyze ARs during…

Solar and Stellar Astrophysics · Physics 2025-09-16 Zahra Tajik , Hasan Rezaei , Mehdi Simiari , Hossien Safari

A solar flare releases magnetic energy by reconnecting field lines across a current sheet, thereby allowing their relaxation to a lower energy state. The maximum possible energy is released if all field lines relax to a current-free…

Solar and Stellar Astrophysics · Physics 2025-11-03 Drake Osaben , Jiong Qiu , Dana W. Longcope

A large-scale, horse-shoe-like filament was investigated and the magnetic field around it was reconstructed. This is an intermediate filament (IF) that appeared on the solar disk for the first time at 02:00 UT on 2015 November 7, and took 8…

Solar and Stellar Astrophysics · Physics 2022-11-16 Kaifeng Kang , Yang Guo , Ilia I. Roussev , Rony Keppens , Jun Lin

Solar energetic events are caused by the release of magnetic energy accumulated in the solar atmosphere. To understand their initiating physical mechanisms, the dynamics of the coronal magnetic fields must be studied. Unfortunately, the…

Solar and Stellar Astrophysics · Physics 2024-08-14 Yeongmin Kang , Takafumi Kaneko , K. D. Leka , Kanya Kusano

An exospheric kinetic solar wind model is interfaced with an observation-driven single fluid magnetohydrodynamic (MHD) model. Initially, a photospheric magnetogram serves as observational input in the fluid approach to extrapolate the…

Solar and Stellar Astrophysics · Physics 2017-10-04 Sofia-Paraskevi Moschou , Viviane Pierrard , Rony Keppens , Jens Pomoell