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Related papers: Coronal energy release by MHD avalanches II. EUV l…

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The heating of the solar chromosphere and corona to the observed high temperatures, imply the presence of ongoing heating that balances the strong radiative and thermal conduction losses expected in the solar atmosphere. It has been…

Coronal rain is the most dramatic cooling phenomenon of the solar corona and an essential diagnostic tool for the coronal heating properties. A puzzling feature of the solar corona, besides the heating, is its EUV filamentary structure and…

This work analyzes the Hall magnetohydrodynamics (HMHD) and magnetohydrodynamics (MHD) numerical simulations of a flaring solar active region as a testbed while idealizing the coronal Alfv\'en speed to be of two orders of magnitude lesser.…

Solar and Stellar Astrophysics · Physics 2022-02-16 Kamlesh Bora , Ramit Bhattacharyya , Avijeet Prasad , Bhuwan Joshi , Qiang Hu

We carry out a three-dimensional magneto-hydrodynamic (MHD) simulation to model the initiation of the coronal mass ejection (CME) on 13 December 2006 in the emerging {\delta}-sunspot active region NOAA 10930. The setup of the simulation is…

Solar and Stellar Astrophysics · Physics 2016-06-22 Yuhong Fan

Combined tearing-thermal evolution plays an important role in the disruption of current sheets, and formation of cool condensations within the solar atmosphere. However, this has received limited attention to date. We numerically explore a…

Solar and Stellar Astrophysics · Physics 2023-10-18 Samrat Sen , Jack Jenkins , Rony Keppens

Solar flares are a major driver of hazardous space weather, whose intense electromagnetic emissions and energetic particles can significantly disturb the near-Earth space environment. Therefore, understanding the physical processes during a…

Solar and Stellar Astrophysics · Physics 2026-02-25 Shihan Li , Jinhan Guo , Wensi Wang , Yu Dai , Brigitte Schmieder , Jaroslav DudÍk , Yang Guo , Mingde Ding

Context. Coronal loops are the basic building blocks of the solar corona, which are related to the mass supply and heating of solar plasmas in the corona. However, their fundamental magnetic structures are still not well understood. Most…

Solar and Stellar Astrophysics · Physics 2020-07-22 Dong Li , Ding Yuan , Marcel Goossens , Tom Van Doorsselaere , Wei Su , Ya Wang , Yang Su , Zongjun Ning

Magnetic flux tubes in the solar corona support a rich variety of transverse oscillations, which are theoretically interpreted as magnetohydrodynamic (MHD) modes with a fast and/or Alfv\'enic character. In the standard flux tube model made…

Solar and Stellar Astrophysics · Physics 2024-12-13 Roberto Soler , Andrew Hillier

Coronal mass ejections (CMEs) and their driven shocks are a major source of large geomagnetic storms due to their large and long-lasting, southward component of magnetic field in the sheath and the flux rope (e.g., magnetic cloud).…

Solar and Stellar Astrophysics · Physics 2024-06-21 Chin-Chun Wu , Kan Liou , Brian Wood , Keiji Hayashi

Magnetic flux emergence from the solar interior to the atmosphere is believed to be a key process of formation of solar active regions and driving solar eruptions. Due to the limited capability of observation, the flux emergence process is…

Solar and Stellar Astrophysics · Physics 2023-01-04 Zhipeng Liu , Chaowei Jiang , Xueshang Feng , Pingbing Zuo , Yi Wang

EUV observations of warm coronal loops suggest that they are bundles of unresolved strands that are heated impulsively to high temperatures by nanoflares. The plasma would then have the observed properties (e.g., excess density compared to…

Solar and Stellar Astrophysics · Physics 2011-02-11 S. Patsourakos , J. A. Klimchuk

Dense plasma fragments were observed to fall back on the solar surface by the Solar Dynamics Observatory after an eruption on 7 June 2011, producing strong EUV brightenings. Previous studies investigated impacts in regions of weak magnetic…

Solar and Stellar Astrophysics · Physics 2016-11-15 A. Petralia , F. Reale , S. Orlando , P. Testa

Turbulent plasma motion is common in the universe, and invoked in solar flares to drive effective acceleration leading to high energy electrons. Unresolved mass motions are frequently detected in flares from extreme ultraviolet (EUV)…

Solar and Stellar Astrophysics · Physics 2023-05-03 Wenzhi Ruan , Limei Yan , Rony Keppens

The Parker model for coronal heating is investigated through a high resolution simulation. An inertial range is resolved where fluctuating magnetic energy E_M (k_perp) \propto k_\perp^{-2.7} exceeds kinetic energy E_K (k_\perp) \propto…

Solar and Stellar Astrophysics · Physics 2011-06-14 A. F. Rappazzo , M. Velli

The Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS) and the Hinode/ EUV Imaging Spectrometer (EIS) observed AR 11726 on 2013 April 23. We present intensity images in numerous atomic lines constructed from these observations. These…

Solar and Stellar Astrophysics · Physics 2018-07-03 Joel Allred , Adrian Daw , Jeffrey Brosius

Condensations in the more than 10^6 K hot corona of the Sun are commonly observed in the extreme ultraviolet (EUV). While their contribution to the total solar EUV radiation is still a matter of debate, these condensations certainly provide…

Solar and Stellar Astrophysics · Physics 2012-09-06 H. Peter , S. Bingert , S. Kamio

In this paper, we study the formation and early evolution of a limb coronal mass ejection (CME) and its associated shock wave that occurred on 2014 January 8. The extreme ultraviolet (EUV) images provided by the Atmospheric Imaging Assembly…

Solar and Stellar Astrophysics · Physics 2016-08-17 Linfeng Wan , Xin Cheng , Tong Shi , Wei Su , M. D. Ding

With the launch of SDO, many EUV waves were observed during solar eruptions. However, the joint observations of Moreton and EUV waves are still relatively rare. We present an event that a small-scale filament eruption simultaneously results…

Solar and Stellar Astrophysics · Physics 2020-05-13 Jincheng Wang , Xiaoli Yan , Defang Kong , Zhike Xue , Liheng Yang , Qiaoling Li

It is largely agreed that many coronal loops---those observed at a temperature of about 1 MK--- are bundles of unresolved strands that are heated by storms of impulsive nanoflares. The nature of coronal heating in hotter loops and in the…

Solar and Stellar Astrophysics · Physics 2015-05-28 Nicholeen M. Viall , James A. Klimchuk

The Parker or field line tangling model of coronal heating is studied comprehensively via long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry within the framework of reduced magnetohydrodynamics…

Astrophysics · Physics 2009-12-06 A. F. Rappazzo , M. Velli , G. Einaudi , R. B. Dahlburg