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Related papers: An Unorthodox X-Class Long-Duration Confined Flare

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Solar post-flare loops (PFLs) are arcade-like loop systems that appear during the gradual phases of eruptive flares. The extreme ultraviolet (EUV) observations from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2016-04-27 Qiao Song , Jing-Song Wang , Xueshang Feng , Xiaoxin Zhang

We analyse multiwavelength observations of a western limb flare (C3.9) occurred in AR NOAA 111465 on 30 April 2012. The high resolution images recorded by SDO/AIA 304, 1600 \AA\ and Hinode/SOT H$\alpha$ show the activation of a…

Solar and Stellar Astrophysics · Physics 2014-12-03 Pankaj Kumar , Kyung-Suk Cho

Eruptive solar flares were predicted to generate large-scale vortex flows at both sides of the erupting magnetic flux rope. This process is analogous to a well-known hydrodynamic process creating vortex rings. The vortices lead to advection…

Solar and Stellar Astrophysics · Physics 2017-08-02 J. Dudík , F. P. Zuccarello , G. Aulanier , B. Schmieder , P. Démoulin

Using the H$\alpha$ observations from the New Vacuum Solar Telescope at Fuxian Solar Observatory, we focus on the fine structures of three confined flares and the issue why all the three flares are confined instead of eruptive. All the…

Solar and Stellar Astrophysics · Physics 2015-06-22 Shuhong Yang , Jun Zhang , Yongyuan Xiang

Recent polarimetric mm-observations of the galactic centre by Wielgus et al. (2022a) showed sinusoidal loops in the Q-U plane with a duration of one hour. The loops coincide with a quasi-simultaneous X-ray flare. A promising mechanism to…

High Energy Astrophysical Phenomena · Physics 2023-09-01 Mahdi Najafi-Ziyazi , Jordy Davelaar , Yosuke Mizuno , Oliver Porth

In this paper, we present a multi-wavelength analysis of two X-class solar eruptive flares of classes X2.2 and X9.3 that occurred in the sigmoidal active region NOAA 12673 on 2017 September 6, by combining observations of Atmospheric…

Solar and Stellar Astrophysics · Physics 2018-12-26 Prabir K. Mitra , Bhuwan Joshi , Avijeet Prasad , Astrid M. Veronig , R. Bhattacharyya

We investigate the occurrence of slipping magnetic reconnection, chromospheric evaporation, and coronal loop dynamics in the 2014 September 10 X-class flare. The slipping reconnection is found to be present throughout the flare from its…

A second peak in extreme ultraviolet sometimes appears during the gradual phase of solar flares, which is known as EUV late phase (ELP). Stereotypically ELP is associated with two separated sets of flaring loops with distinct sizes, and it…

Solar and Stellar Astrophysics · Physics 2020-10-13 Jun Chen , Rui Liu , Kai Liu , Arun Kumar Awasthi , Pejin Zhang , Yuming Wang , Bernhard Kliem

Most stellar flares' soft X-ray lightcurves possess a `typical' morphology, which consists of a rapid rise followed by a slow exponential decay. However, a study of 216 of the brightest flares on 161 pre-main sequence stars, observed during…

Solar and Stellar Astrophysics · Physics 2015-05-30 C. P. Johnstone , S. G. Gregory , M. M. Jardine , K. V. Getman

We present observations of a confined M4.0 flare from NOAA 11302 on 2011 September 26. Observations at high temporal, spatial, and spectral resolution from Solar Dynamics Observatory, Reuven Ramaty High Energy Solar Spectroscopic Imager,…

Solar and Stellar Astrophysics · Physics 2014-08-05 Upendra Kushwaha , Bhuwan Joshi , Kyung-Suk Cho , Astrid Veronig , Sanjiv Kumar Tiwari , S. K. Mathew

We investigate the formation and magnetic topology of four flare/CME events with filament-sigmoid systems, in which the sigmoidal hot channels are located above the filaments, and they appear in pairs prior to eruption.} The formation of…

Solar and Stellar Astrophysics · Physics 2018-11-28 Tie Liu , Yingna Su , Xin Cheng , Adriaan van Ballegooijen , Haisheng Ji

We report seven examples of a long-ignored type of confined solar flare eruption that does not fit the standard model for confined flare eruptions. Because they are confined eruptions, do not fit the standard model, and unexpectedly erupt…

Solar and Stellar Astrophysics · Physics 2024-08-20 Ronald L. Moore , Sanjiv K. Tiwari , Navdeep K. Panesar , V. Aparna , Alphonse C. Sterling

On 2024 May 6, Active Region 13663 produced an X4.5-class flare associated with a filament eruption that exhibited remarkable rotation and deflection dynamics. This study aims to investigate two key aspects of this event: the formation…

Solar and Stellar Astrophysics · Physics 2026-04-28 Xiaomeng Zhang , Jinhan Guo , Yang Guo , Mingde Ding , Brigitte Schmieder

We studied the rapid filament evolution in AR 12975 during a confined C2 flare on 28 March 2022, which led to an eruptive M4 flare 1.5 h later. It is characterized by the breakup of the filament, the disappearance of its southern half, and…

Multi-instrument observations of NOAA AR10938 on Jan. 14-18, 2007, are utilized to study the evolution of a magnetic thread system with multiple crossings suggestive of a twisted coronal flux rope. A C-class flare recorded by GOES on Jan.…

Solar and Stellar Astrophysics · Physics 2009-02-04 Nour-Eddine Raouafi

Cool stars are known to produce flares probably as a result of magnetic reconnection in their outer atmospheres. We present simultaneous XMM-Newton optical V band and X-ray observations of the M8 dwarf LP412-31. During the observation a…

Astrophysics · Physics 2009-11-11 B. Stelzer , J. H. M. M. Schmitt , G. Micela , C. Liefke

The asymmetry in hard X-ray (HXR) emission at the footpoints (FPs) of flare loops is a ubiquitous feature closely associated with nonthermal electron transport. We analyze the asymmetric HXR radiation at two flare ribbons which is…

Solar and Stellar Astrophysics · Physics 2024-07-19 Guanglu Shi , Li Feng , Jun Chen , Beili Ying , Shuting Li , Qiao Li , Hui Li , Ying Li , Kaifan Ji , Yu Huang , Weiqun Gan , the LST team

We study the spectral and temporal behavior of X-ray flares from the active M-dwarf EV Lac in 200 ks of exposure with the Chandra/HETGS. We derive flare parameters by fitting an empirical function which characterizes the amplitude, shape,…

High Energy Astrophysical Phenomena · Physics 2015-05-19 David P. Huenemoerder , Norbert S. Schulz , Paola Testa , Jeremy J. Drake , Rachel A. Osten , Fabio Reale

Magnetic flux ropes (MFRs), sets of coherently twisted magnetic field lines, are believed as core structures of various solar eruptions. Their evolution plays an important role to understand the physical mechanisms of solar eruptions, and…

Solar and Stellar Astrophysics · Physics 2023-01-11 Ruisheng Zheng , Yihan Liu , Liang Zhang , Yang Liu , Changhui Rao , Qing Lin , Zhimao Du , Libo Zhong , Huadong Chen , Yao Chen

This paper presents the multi-wavelength analysis of a 13 s quasi-periodic pulsation (QPP) observed in hard X-ray (12-300 keV) and microwave (4.9-34 GHz) emissions during a C-class flare occurred on 21 September 2015. AIA 304 and 171 \AA~…

Solar and Stellar Astrophysics · Physics 2017-02-22 Pankaj Kumar , Valery M. Nakariakov , Kyung-Suk Cho