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Related papers: Sunspot waves and flare energy release

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We present multispectral analysis (radio, H$\alpha$, UV/EUV, and hard X-ray) of a confined flare from 2015 March 12. This flare started within the active region NOAA 12 297 and then it expanded into a large preexisting magnetic rope…

Solar and Stellar Astrophysics · Physics 2021-01-22 Alena Zemanová , Marian Karlický , Jana Kašparová , Jaroslav Dudík

The strong correlation between energy injection and mid-infrared (mid-IR) emission observed during solar flares can be used to probe energy deposition throughout the chromosphere, since the IR tracks prompt flare-induced changes in electron…

Solar and Stellar Astrophysics · Physics 2026-05-08 Miguel Rojas-Quesada , Lyndsay Fletcher , Hugh Hudson , Sargam M. Mulay , Paulo J. A. Simoes

We present results revealing microwave pulsations produced in a model of a flaring twisted solar coronal loop, without any external oscillatory driver. Two types of oscillations are identified: slowly-decaying oscillations with a period of…

Solar and Stellar Astrophysics · Physics 2022-02-09 C. Smith , M. Gordovskyy , P. K. Browning

Recent observations in extreme-ultraviolet (EUV) wavelengths reveal an EUV late phase in some solar flares, which is characterized by a second peak in the warm coronal emissions (about 3 MK) occurring several tens of minutes to a few hours…

Solar and Stellar Astrophysics · Physics 2023-07-19 Yuehong Chen , Yu Dai , Mingde Ding

We investigate accelerated electron energy spectra for different sources in a large flare using simultaneous observations obtained with two instruments, the Nobeyama Radio Heliograph (NoRH) at 17 and 34 GHz, and the Reuven Ramaty High…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. R. Kundu , V. V. Grechnev , S. M. White , E. J. Schmahl , N. S. Meshalkina , L. K. Kashapova

Using observations from the Solar Dynamics Observatory's Atmosphere Imaging Assembly and the Ramaty High Energy Solar Spectroscopic Imager, we present novel measurements of the shear of post-reconnection flare loops (PRFLs) in…

Solar and Stellar Astrophysics · Physics 2023-08-17 J. Qiu , M. Alaoui , S. K. Antiochos , J. T. Dahlin , M. Swisdak , J. F. Drake , A. Robison , C. R. DeVore , V. M. Uritsky

The evolution of an X2.7 solar flare, that occurred in a complex $\beta\gamma\delta$ magnetic configuration region on 2003 November 3 is discussed utilizing a multi-wavelength data set. The very first signature of pre-flare coronal activity…

Astrophysics · Physics 2009-11-13 Bhuwan Joshi , P. K. Manoharan , Astrid M. Veronig , P. Pant , Kavita Pandey

Aims: Changes of the magnetic field and the line-of-sight velocities in the photosphere are being reported for an M-class flare that originated at a $\delta$-spot belonging to active region NOAA 11865. Methods: High-resolution ground-based…

In this multi-instrument paper, we search for evidence of sustained magnetic reconnection far beyond the impulsive phase of the X8.2-class solar flare on 2017 September 10. Using Hinode/EIS, CoMP, SDO/AIA, K-Cor, Hinode/XRT, RHESSI, and…

Solar and Stellar Astrophysics · Physics 2020-10-01 Ryan J. French , Sarah A. Matthews , Lidia van Driel-Gesztelyi , David M. Long , Philip G. Judge

The energy released in a solar flare is partitioned between thermal and non-thermal particle energy and lost to thermal conduction and radiation over a broad range of wavelengths. It is difficult to determine the conductive losses and the…

Astrophysics · Physics 2011-02-11 J. C. Raymond , G. Holman , A. Ciaravella , A. Panasyuk , Y. -K. Ko , J. Kohl

Using a simple two-dimensional, zero-beta model, we explore the manner by which reconnection at a current sheet releases and dissipates free magnetic energy. We find that only a small fraction (3%-11% depending on current sheet size) of the…

Solar and Stellar Astrophysics · Physics 2015-06-05 Dana Longcope , Lucas Tarr

Solar flares typically have an impulsive phase that followed by a gradual phase as best seen in soft X-ray emissions. A recent discovery based on the EUV Variability Experiment (EVE) observations onboard the Solar Dynamics Observatory (SDO)…

Solar and Stellar Astrophysics · Physics 2015-04-22 Kai Liu , Jie Zhang , Yuming Wang , Xin Cheng

Solar flare simulations are commonly initialised using non-linear force free field (NLFF) extrapolations derived from photospheric vector magnetograms. However, the force free assumption neglects plasma forces and may limit the available…

Solar and Stellar Astrophysics · Physics 2026-05-15 W. Bate , M. Gordovskyy , A. Prasad , A. S. Brun , A. Strugarek , M. V. Sieyra , P. Browning , S. Inoue , K. Matsumoto , A. Roddanavar

We studied a solar flare with pronounced quasi-periodic pulsations detected in the microwave, X-ray, and radio bands. We used the methods of correlation, Fourier, and wavelet analyses to examine the temporal fine structures and…

Solar and Stellar Astrophysics · Physics 2016-08-02 E. G. Kupriyanova , L. K. Kashapova , H. A. S. Reid , I. N. Myagkova

Plasmoids (or magnetic islands) are believed to play an important role in the onset of fast magnetic reconnection and particle acceleration during solar flares and eruptions. Direct imaging of flare current sheets and formation/ejection of…

Solar and Stellar Astrophysics · Physics 2025-01-22 Pankaj Kumar , Judith T. Karpen , Joel T. Dahlin

The energy released during solar flares is believed to be stored in non-potential magnetic fields associated with electric currents flowing in the corona. While no measurements of coronal electric currents are presently available, maps of…

Solar and Stellar Astrophysics · Physics 2015-08-19 Sophie Musset , Nicole Vilmer , Véronique Bommier

We investigate quasi-periodic coronal pulsations during the decay phase of an X 3.2 class flare on 14 May 2013, using soft X-ray data from the RHESSI satellite. Periodogram analyses of soft X-ray light curves show that 53 s and 72 s periods…

Solar and Stellar Astrophysics · Physics 2016-01-20 Partha Chowdhury , A. K. Srivastava , B. N. Dwivedi , Robert Sych , Y. -J. Moon

We study the relationship between implosive motions in a solar flare, and the energy redistribution in the form of oscillatory structures and particle acceleration. The flare SOL2012-03-09T03:53 (M6.4) shows clear evidence for an…

Solar and Stellar Astrophysics · Physics 2015-06-17 P. J. A. Simões , L. Fletcher , H. S. Hudson , A. J. B. Russell

Solar flares are powerful particle accelerators, and in the accepted standard flare model most of the flare energy is transported from a coronal energy-release region by accelerated electrons which stop collisionally in the chromosphere,…

Solar and Stellar Astrophysics · Physics 2024-06-18 Paulo J. A. Simões , Lyndsay Fletcher , Hugh S. Hudson , Graham S. Kerr , Matt Penn , Karla F. Lopez

Sunspot proper motions and flares of a super active region NOAA 5395, which was the biggest and the most flare-active region in the 22nd sunspot cycle, were analyzed in details. We measured sunspot proper motions by using the H-alpha - 5.0…

Astrophysics · Physics 2009-10-30 Takako T. Ishii , Hiroki Kurokawa , Tsutomu T. Takeuchi