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Related papers: Post-flare evolution of AR 10923 with Hinode/XRT

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Magnetic twist of the active region has been measured over a decade using photospheric vector field data, chromospheric H_alpha data, and coronal loop data. The twist and tilt of the active regions have been measured at the photospheric…

Solar and Stellar Astrophysics · Physics 2017-08-02 B. Ravindra , P. Venkatakrishnan , Sanjiv Kumar Tiwari

Aims: This work aims to identify the mechanism driving pulsations in hard X-ray (HXR) and microwave emission during solar flares. Here, by using combined HXR and microwave observations from Solar Orbiter/STIX and EOVSA we investigate an…

Solar and Stellar Astrophysics · Physics 2024-05-01 Hannah Collier , Laura A. Hayes , Sijie Yu , Andrea F. Battaglia , William Ashfield , Vanessa Polito , Louise K. Harra , Säm Krucker

On 2024 May 10/11, the strongest geomagnetic storm since November 2003 has occurred, with a peak Dst index of -412 nT. The storm was caused by NOAA Active Region (AR) 13664, which was the source of a large number of coronal mass ejections…

Solar and Stellar Astrophysics · Physics 2024-09-13 Robert Jarolim , Astrid Veronig , Stefan Purkhart , Peijin Zhang , Matthias Rempel

On the 29 March 2014 NOAA active region (AR) 12017 produced an X1 flare which was simultaneously observed by an unprecedented number of observatories. We have investigated the pre-flare period of this flare from 14:00 UT until 19:00 UT…

Solar and Stellar Astrophysics · Physics 2017-03-08 M. M. Woods , L. K. Harra , S. A. Matthews , D. H. Mackay , S. Dacie , D. M. Long

We present observations of a B7.9-class flare that occurred on the 24th January, 2015, using the Atmopsheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO), the EUV Imaging Spectrometer (EIS) and the X-Ray Telescope of…

Solar and Stellar Astrophysics · Physics 2017-03-29 Giuseppe Nisticò , Vanessa Polito , Valery M. Nakariakov , Giulio del Zanna

Solar flares are sudden and violent releases of magnetic energy in the solar atmosphere that can be divided in eruptive flares, when plasma is ejected from the solar atmosphere, resulting in a coronal mass ejection (CME), and confined…

Solar and Stellar Astrophysics · Physics 2017-05-24 F. P. Zuccarello , R. Chandra , B. Schmieder , G. Aulanier , R. Joshi

Stellar flares affect all atmospheric layers from the photosphere over chromosphere and transition region up into the corona. Simultaneous observations in different spectral bands allow to obtain a comprehensive picture of the environmental…

Solar and Stellar Astrophysics · Physics 2015-05-18 Carolin Liefke , Birgit Fuhrmeister , Juergen H. M. M. Schmitt

We aim to better characterize the conditions of the solar corona, especially with respect to the occurrence of confined and eruptive flares. In this work, we model the coronal evolution around 231 large flares observed during solar cycle…

Solar and Stellar Astrophysics · Physics 2025-01-29 Julia K. Thalmann , Manu Gupta , Astrid M. Veronig , Yang Liu

Solar flares are driven by release of the free magnetic energy and its conversion to other forms of energy -- kinetic, thermal, and nonthermal. Quantification of partitions between these energy components and their evolution is needed to…

Solar and Stellar Astrophysics · Physics 2023-08-02 Gregory D. Fleishman , Gelu M. Nita , Galina G. Motorina

Magnetohydrodynamic (MHD) plasma turbulence is believed to play a vital role in the production of energetic electrons during solar flares and the non-thermal broadening of spectral lines is a key sign of this turbulence. Here, we determine…

Solar and Stellar Astrophysics · Physics 2021-12-22 Morgan Stores , Natasha L. S. Jeffrey , Eduard P. Kontar

This Letter is to investigate the physics of a newly discovered phenomenon -- contracting flare loops in the early phase of solar flares. In classical flare models, which were constructed based on the phenomenon of expansion of flare loops,…

Astrophysics · Physics 2009-11-13 Jinhua Shen , Tuanhui Zhou , Haisheng Ji , Na Wang , Wenda Cao , Haimin Wang

Using data from observations made with XMM-Newton, we present an X-ray analysis of two flares observed in $\xi$ Boo. The flare loop parameters are derived using various loop models including state-of-the-art hydrodynamic flare model. The…

Solar and Stellar Astrophysics · Physics 2017-08-02 J. C. Pandey , A. K. Srivastava

We observe the motion of cool and hot plasma in a multi-stranded post flare loop system that evolved in the decay phase of a two ribbon M1.0 class flare in AR 11093 on 7 August 2010 using SDO/AIA 304 \AA\ and 171 \AA\ filters. The moving…

Solar and Stellar Astrophysics · Physics 2015-05-30 Abhishek K. Srivastava , K. Murawski

We investigated the response of the solar atmosphere to non-thermal electron beam heating using the radiative transfer and hydrodynamics modelling code RADYN. The temporal evolution of the parameters that describe the non-thermal electron…

Solar and Stellar Astrophysics · Physics 2015-06-10 Michael B. Kennedy , Ryan O. Milligan , Joel C. Allred , Mihalis Mathioudakis , Francis P. Keenan

Solar flares are complex phenomena driven by the release of magnetic energy, but a large energy reservoir is not sufficient to determine their eruptive potential; the magnetic topology and plasma dynamics play a key role. We investigate the…

Solar and Stellar Astrophysics · Physics 2026-03-04 C. J. Díaz Baso , J. de la Cruz Rodríguez , H. -P. Doerr , M. van Noort , A. Prasad , A. Feller , D. Kiselman

We present a 3D MHD simulation that qualitatively models the coronal mag- netic field evolution associated with the eruptive flare that occurred on December 13, 2006 in the emerging {\delta}-sunspot region NOAA 10930 observed by the Hinode…

Solar and Stellar Astrophysics · Physics 2015-05-30 Y. Fan

We investigate the thermal properties of a solar flare by the observations of soft X-ray Telescope (XRT) on board Hinode and the Atmospheric Image Assembly on board the Solar Dynamics Observatory (SDO/AIA). Our analysis reveals a tenuous…

Solar and Stellar Astrophysics · Physics 2025-10-22 Xiaoyan Xie , Anna Chen , Crisel Suarez , Katharine K. Reeves , Soumya Roy , Christopher S. Moore , Nishu Karna , Joy Velasquez

Magnetic flux ropes (FRs) are twisted structures appearing on the sun, predominantly in the magnetically concentrated regions. These structures appear as coronal features known as filaments or prominences in H$\alpha$ observations, and as…

Solar and Stellar Astrophysics · Physics 2024-10-04 P. Vemareddy

We analyze and model a C5.7 two-ribbon solar flare observed by SDO, Hinode and GOES on 2011 December 26. The flare is made of many loops formed and heated successively over one and half hours, and their footpoints are brightened in the UV…

Solar and Stellar Astrophysics · Physics 2018-04-04 Chunming Zhu , Jiong Qiu , Dana W. Longcope

Multi-instrument data sets of NOAA AR10938 on Jan. 16, 2007, (e.g., {\emph{Hinode}}, {\it{STEREO}}, {\it{GOES}}, {\it{MLSO}} and {\it{ISOON}} H$\alpha$) are utilized to study the fine structure and evolution of a magnetic loop system…

Solar and Stellar Astrophysics · Physics 2009-11-13 N. -E. Raouafi