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Related papers: Fractal Reconnection in Solar and Stellar Environm…

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Solar flares are the largest energy-release events in the Solar System, allowing us to study fundamental physical phenomena under extreme conditions. Those include magnetic reconnection, particle acceleration, radiation transport, and…

Recently, many superflares on solar-type stars were discovered as white-light flares (WLFs). A correlation between the energies (E) and durations (t) of superflares is derived as $t\propto E^{0.39}$, and this can be theoretically explained…

The evolution of the spectral energy distribution during flares constrains models of particle acceleration in blazar jets. The archetypical blazar BL Lac provided a unique opportunity to study spectral variations during an extended strong…

High Energy Astrophysical Phenomena · Physics 2023-03-15 S. Agarwal , B. Banerjee , A. Shukla , J. Roy , S. Acharya , B. Vaidya , V. R. Chitnis , S. M. Wagner , K. Mannheim , M. Branchesi

Sunspots are concentrations of magnetic field visible on the solar surface (photosphere). It was considered implausible that solar flares, as resulted from magnetic reconnection in the tenuous corona, would cause a direct perturbation of…

Solar and Stellar Astrophysics · Physics 2017-05-12 Chang Liu , Yan Xu , Wenda Cao , Na Deng , Jeongwoo Lee , Hugh S. Hudson , Dale E. Gary , Jiasheng Wang , Ju Jing , Haimin Wang

Recent observations at high spatial resolution have shown that magnetic flux cancellation occurs on the solar surface much more frequently than previously thought, and so this led Priest et al 2018 to propose magnetic reconnection driven by…

Solar and Stellar Astrophysics · Physics 2019-02-13 P. Syntelis , E. R. Priest , L. P. Chitta

Solar flares sometimes lead to coronal mass ejections that directly affect the Earth's environment. However, a large fraction of flares, including on solar-type stars, are confined flares. What are the differences in physical properties…

Solar and Stellar Astrophysics · Physics 2023-10-18 Maria D. Kazachenko

The gamma-ray space telescopes AGILE and Fermi detected short and bright synchrotron gamma-ray flares at photon energies above 100 MeV in the Crab Nebula. This discovery suggests that electron-positron pairs in the nebula are accelerated to…

High Energy Astrophysical Phenomena · Physics 2015-05-30 Benoit Cerutti , Dmitri A. Uzdensky , Mitchell C. Begelman

Solar eruptive events such as coronal mass ejections and eruptive flares are frequently associated with the emergence of magnetic flux from the convection zone into the corona. We use three dimensional magnetohydrodynamic numerical…

Solar and Stellar Astrophysics · Physics 2022-07-27 James Leake , Mark Linton , Spiro Antiochos

Theoretically, CME kinematics are related to magnetic reconnection processes in the solar corona. However, the current quantitative understanding of this relationship is based on the analysis of only a handful of events. Here we report a…

Solar and Stellar Astrophysics · Physics 2020-05-06 Chunming Zhu , Jiong Qiu , Paulett Liewer , Angelos Vourlidas , Michael Spiegel , Qiang Hu

UV bursts are transients in the solar atmosphere with an increased impulsive emission in the extreme UV lasting for one to several tens of minutes. They often show spectral profiles indicative of a bi-directional outflow in response to…

Solar and Stellar Astrophysics · Physics 2019-07-31 H. Peter , Y. -M. Huang , L. P. Chitta , P. R. Young

Magnetic reconnection plays a crucial role in powering solar flares, production of energetic particles, and plasma heating. However, where the magnetic reconnections occur, how and where the released magnetic energy is transported, and how…

Solar and Stellar Astrophysics · Physics 2020-09-02 Sijie Yu , Bin Chen , Katharine K. Reeves , Dale E. Gary , Sophie Musset , Gregory D. Fleishman , Gelu M. Nita , Lindsay Glesener

Magnetic reconnection is widely believed to be the fundamental process in the solar atmosphere that underlies magnetic energy release and particle acceleration. This process is responsible for the onset of solar flares, coronal mass…

Solar and Stellar Astrophysics · Physics 2024-07-17 Pankaj Kumar , Judith T. Karpen , Vasyl Yurchyshyn , C. Richard DeVore , Spiro K. Antiochos

Most models of solar eruptions assume that coronal field lines are anchored in the dense photosphere and thus the photospheric magnetic fields would not have rapid, irreversible changes associated with eruptions resulted from the coronal…

Solar and Stellar Astrophysics · Physics 2015-05-19 Haimin Wang , Chang Liu

Context. We introduce a model for including accelerated particles in pure magnetohydrodynamics (MHD) simulations of the solar atmosphere. Aims. We show that the method is viable and produces results that enhance the realism of MHD…

Solar and Stellar Astrophysics · Physics 2018-12-05 Helle Bakke , Lars Frogner , Boris Vilhelm Gudiksen

In the standard model of solar flares, a large-scale reconnection current sheet is postulated as the central engine for powering the flare energy release and accelerating particles. However, where and how the energy release and particle…

The solar wind originates from regions of open magnetic fields on the Sun, but the relevant processes remain unsolved. We present a self-consistent numerical model of the source region of the wind, in which jets similar to those observed on…

Solar and Stellar Astrophysics · Physics 2025-09-17 Yajie Chen , Hardi Peter , Damien Przybylski , Haruhisa Iijima , Lakshmi Pradeep Chitta

Certain solar flares exhibit a distinctive candle-flame or cusp-shaped feature above the bright flare arcade visible in extreme ultraviolet (EUV) and X-ray channels sensitive to high-temperature plasma. The presence of a cusp-like structure…

Solar and Stellar Astrophysics · Physics 2026-05-19 Ivan Oparin , Sabastian Fernandes , Bin Chen , Chengcai Shen , Xiaocan Li , Fan Guo , Sijie Yu

Magnetic reconnection modulated by non-local disturbances in the solar atmosphere has been investigated theoretically, but rarely observed. In this study, employing Ha and extreme ultraviolet (EUV) images and line of sight magnetograms, we…

Solar and Stellar Astrophysics · Physics 2021-03-10 Leping Li , Hardi Peter , Lakshmi Pradeep Chitta , Hongqiang Song , Kaifan Ji , Yongyuan Xiang

Solar flares and coronal mass ejections (CMEs) are closely coupled through magnetic reconnection. CMEs are usually accelerated impulsively within the low solar corona, synchronized with the impulsive flare energy release. We investigate the…

Solar flares are large explosions on the Sun's surface caused by a sudden release of magnetic energy. They are known to cause local short-lived oscillations travelling away from the explosion like water rings. Here we show that the energy…

Astrophysics · Physics 2009-11-13 C. Karoff , H. Kjeldsen