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Related papers: Soft X-ray Pulsations in Solar Flares

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Small scale extreme ultraviolet (EUV) transient brightenings are observationally abundant and critically important to investigate. Determining whether they share the same physical mechanisms as larger scale flares would have significant…

Doppler shifts in chromospheric and transition-region lines during solar flares are often interpreted as chromospheric condensation or evaporation. However, alternative sources of Doppler-shifted emission have been suggested, such as…

Solar and Stellar Astrophysics · Physics 2025-09-08 Luke H. Majury , Ryan O. Milligan

The hard X-ray emission in a solar flare is typically characterized by a number of discrete sources, each with its own spectral, temporal, and spatial variability. Establishing the relationship amongst these sources is critical to determine…

Solar and Stellar Astrophysics · Physics 2018-08-08 Federica Sciacchitano , Alberto Sorrentino , A Gordon Emslie , Anna Maria Massone , Michele Piana

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 have performed the first polarimetry of solar flare emission at gamma-ray energies (0.2-1 MeV). These observations were performed with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) for two large flares: the GOES…

Astrophysics · Physics 2009-11-13 Steven E. Boggs , W. Coburn , E. Kalemci

X-ray emission provides the most direct diagnostics of the energy-release process in solar flares. Occasionally, a superhot X-ray source is found to be above hot flare loops of ~10 MK temperature. While the origin of the superhot plasma is…

Solar and Stellar Astrophysics · Physics 2022-02-09 Zhenjun Zhou , Rui Liu , Jianqing Sun , Jie Zhang , Mingde Ding , Yuming Wang , Xiaoyu Yu , Lijuan Liu , Jun Cui

The discovery of hard X-ray sources near the top of a flaring loop by the HXT instrument on board the YOHKOH satellite represents a significant progress towards the understanding of the basic processes driving solar flares. In this paper we…

Astrophysics · Physics 2009-11-07 Vahe' Petrosian , Timothy Q. Donaghy , James M. McTiernan

Using the ULTRASPEC instrument mounted on the 2.4-m Thai National Telescope, we observed two large flares, each with a total energy close to 10^34 erg with sub-second cadence. A combination of a wavelet analysis, a Fourier transform plus an…

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

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

Multi--wavelength studies of energetic solar flares with seismic emissions have revealed interesting common features between them. We studied the first GOES X--class flare of the 24th solar cycle, as detected by the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2015-06-04 J. D. Alvarado-Gómez , J. C. Buitrago-Casas , J. C. Martínez-Oliveros , C. Lindsey , H. Hudson , B. Calvo-Mozo

A peculiar microwave quasi-periodic pulsation with zigzag pattern (Z-QPP) is observed first by the Chinese Solar Broadband Spectrometer in Huairou (SBRS/Huairou) at 1.10-1.34 GHz in a solar flare on 2005-01-15. The Z-QPP occurred just in…

Solar and Stellar Astrophysics · Physics 2013-06-14 Baolin Tan

Abridged. We observed the 40 Myr old star DS Tuc A with XMM-Newton and recorded two X-ray bright flares, with the second event occurring about 12 ks after the first one. Their duration from the rise to the end of the decay was of about 8-10…

Solar and Stellar Astrophysics · Physics 2022-10-26 I. Pillitteri , C. Argiroffi , A. Maggio , G. Micela , S. Benatti , F. Reale , S. Colombo , S. J. Wolk

We present direct evidence for the detection of the main energy release site in a non-eruptive solar flare, SOL2013-11-09T06:38UT. This GOES C2.7 event was characterised by two flaring ribbons and a compact, bright coronal source located…

Solar and Stellar Astrophysics · Physics 2015-05-06 Paulo J. A. Simões , David R. Graham , Lyndsay Fletcher

For the 2017 September 6 flare (SOL2017-Sep-06T11:53) we present not only unusual radio bursts, but also their interesting time association with the other flare phenomena observed in EUV, white-light, X-ray, and $\gamma$-ray emissions.…

Solar and Stellar Astrophysics · Physics 2020-10-07 M. Karlicky , J. Rybak

The aim of the present paper is to use quasi-periodic oscillations in hard X-rays (HXRs) of solar flares as a diagnostic tool for investigation of impulsive electron acceleration. We have selected a number of flares which showed…

Solar and Stellar Astrophysics · Physics 2015-05-13 J. Jakimiec , M. Tomczak

Solar flares are currently understood as the explosive release of energy stored in the form of stressed magnetic fields. In many cases, the released energy seems to take the form of large numbers of electrons accelerated to high energies or…

Solar and Stellar Astrophysics · Physics 2010-05-18 George H. Fisher

Flares are powerful events ignited by a sudden release of magnetic energy. With the aim of studying flares in the 125-Myr-old stars in the Pleiades observed simultaneously in optical and X-ray light, we obtained new XMM-Newton observations…

The discovery of quasi-periodic brightness oscillations (QPOs) in the X-ray emission accompanying the giant flares of the soft gamma-ray repeaters SGR 1806-20 and SGR 1900+14 has led to intense speculation about their nature and what they…

High Energy Astrophysical Phenomena · Physics 2019-08-21 M. Coleman Miller , Cecilia Chirenti , Tod Strohmayer

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
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