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In this paper, we identify the magnetic reconnections at the hyperbolic flux tube (HFT), aided by slipping reconnection at quasi-separatrix layers (QSLs), which are pivotal to the occurrence of a confined M2.1 class flare in NOAA active…

Solar and Stellar Astrophysics · Physics 2026-04-14 Pawan Kumar , Sadashiv , Sanjay Kumar , Sushree S. Nayak , Simrat Kaur , Ramit Bhattacharya

The solar magnetic field is key to understanding the physical processes in the solar atmosphere. Nonlinear force-free codes have been shown to be useful in extrapolating the coronal field upward from underlying vector boundary data.…

Astrophysics · Physics 2008-02-29 T. Wiegelmann , J. K. Thalmann , C. J. Schrijver , M. L. Derosa , T. R. Metcalf

Knowledge of electric fields in the photosphere is required to calculate the electromagnetic energy flux through the photosphere and set up boundary conditions for data-driven magnetohydrodynamic (MHD) simulations of solar eruptions.…

Solar and Stellar Astrophysics · Physics 2021-09-22 Andrey N. Afanasyev , Maria D. Kazachenko , Yuhong Fan , George H. Fisher , Benoit Tremblay

As well known, magnetic fields in space are distributed very inhomogeneously. Some-times field distributions have forms of filaments with high magnetic field values. As many ob-servations show, such a filamentation takes place in convective…

Solar and Stellar Astrophysics · Physics 2024-03-03 Evgeny A. Kuznetsov , Evgeny A. Mikhailov

Context: Solar magnetic fields are regularly extrapolated into the corona starting from photospheric magnetic measurements that can suffer from significant uncertainties. Aims: Here we study how inaccuracies introduced into the maps of the…

Solar and Stellar Astrophysics · Physics 2015-05-14 T. Wiegelmann , L. Yelles Chaouche , S. K. Solanki , A. Lagg

We explore the processes of repetitive build-up and explosive release of magnetic energy together with the formation of magnetic flux ropes that eventually resulted into three homologous eruptive flares of successively increasing…

Solar and Stellar Astrophysics · Physics 2023-02-08 Suraj Sahu , Bhuwan Joshi , Avijeet Prasad , Kyung-Suk Cho

Active region (AR) 12673 produced many M-class and several X-class flares, one of which being an X9.3 flare, which is recorded as the largest solar flare in solar cycle 24. We studied the evolution of the three-dimensional flare-productive…

Solar and Stellar Astrophysics · Physics 2021-02-24 Daiki Yamasaki , Satoshi Inoue , Shin'ichi Nagata , Kiyoshi Ichimoto

The effect of using two representations of the normal-to-surface magnetic field to calculate photospheric measures that are related to active region (AR) potential for flaring is presented. Several AR properties were computed using…

Solar and Stellar Astrophysics · Physics 2018-01-24 Jordan A. Guerra , Sung-H. Park , Ioannis Kontogiannis , Peter T. Gallagher , Manolis Georgoulis , D. Shaun Bloomfield

Results from a numerical study of fluctuation dynamo in a collisionless, weakly magnetized plasma are presented. The key difference between this dynamo and its magnetohydrodynamic (MHD) counterpart is the adiabatic production of…

High Energy Astrophysical Phenomena · Physics 2018-08-17 Denis A. St-Onge , Matthew W. Kunz

Magnetohydrodynamics (MHD) is a subject concerned with the dynamics of electrically conducting fluids (plasma) and can be applied in electric power generation. As a unique technology for producing direct-current electricity without moving…

Plasma Physics · Physics 2023-12-15 Osama A. Marzouk

To understand the physics of solar flares, including the local reorganisation of the magnetic field and the acceleration of energetic particles, we have first to estimate the free magnetic energy available for such phenomena, which can be…

Astrophysics · Physics 2008-05-16 S. Regnier , E. R. Priest

The separation of a filament and sigmoid is observed during an X1.4 flare on July 12, 2012 in solar active region 11520, but the corresponding magnetic field change is not clear. We construct a data-constrained magnetohydrodynamic…

Solar and Stellar Astrophysics · Physics 2022-11-30 Tie Liu , Yuhong Fan , Yingna Su , Yang Guo , Ya Wang , Haisheng Ji

The photospheric magnetic field vector is continuously derived from measurements, while reconstruction of the three-dimensional (3D) coronal magnetic field requires modelling with photospheric measurements as a boundary condition. For…

Solar and Stellar Astrophysics · Physics 2022-03-23 I. Chifu , B. Inhester , T. Wiegelmann

In this paper, the statistical studies on the force-freeness of photosphere magnetic fields are given. The studies are based on the vector magnetic fields observed by Solar Optical Telescope/Spectro-Polarimeter (SOT/SP) on board Hinode.…

Solar and Stellar Astrophysics · Physics 2019-02-04 S. Liu , J. Hao

Context. Magnetic bright points (MBPs) are dynamic, small-scale magnetic elements often found with field strengths of the order of a kilogauss within intergranular lanes in the photosphere. Aims. Here we study the evolution of various…

We present the photospheric energy density of magnetic fields in two solar active regions inferred from observational vector magnetograms, and compare it with the possible different defined energy parameters of magnetic fields in the…

Solar and Stellar Astrophysics · Physics 2016-12-12 Hongqi Zhang

We propose a magnetic confinement nuclear fusion mechanism for the evolution of a solar flare in solar atmosphere. The mechanism agree with two observed characteristics of explosive flares and coronal mass ejections (CMEs) that have proved…

Solar and Stellar Astrophysics · Physics 2020-03-11 Ying-Zhi Zhang

This work is a continuation of Paper I [Sharykin et al., 2018] devoted to analysis of nonthermal electron dynamics and plasma heating in the confined M1.2 class solar flare SOL2015-03-15T22:43 revealing energy release in the highly sheared…

Solar and Stellar Astrophysics · Physics 2020-05-06 I. N. Sharykin , I. V. Zimovets , I. I. Myshyakov

In order to bridge the gap between heliospheric and solar observations of coronal mass ejections (CMEs), one of the key steps is to improve the understanding of their corresponding magnetic structures like the magnetic flux ropes (MFRs).…

Solar and Stellar Astrophysics · Physics 2022-08-03 Wen He , Qiang Hu , Chaowei Jiang , Jiong Qiu , Avijeet Prasad

In this work, we investigate the formation of a magnetic flux rope (MFR) above the central polarity inversion line (PIL) of NOAA Active Region 12673 during its early emergence phase. Through analyzing the photospheric vector magnetic field,…

Solar and Stellar Astrophysics · Physics 2019-10-15 Lijuan Liu , Xin Cheng , Yuming Wang , Zhenjun Zhou