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Related papers: Impulsivity Parameter for Solar Flares

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Solar flares are sudden energy release events in the solar corona, resulting from magnetic reconnection, that accelerates particles and heats the ambient plasma. During a flare, there are often multiple, temporally and spatially separated…

Solar and Stellar Astrophysics · Physics 2020-12-02 Rohit Sharma , Marina Battaglia , Yingjie Luo , Bin Chen , Sijie Yu

Properties of the solar radio spectrum, as well as the temporal profiles of flare emission, indicate the thermal nature of the sub-terahertz (sub-THz) component observed as the growth of radio emission in the frequency range of 100-1000…

Solar and Stellar Astrophysics · Physics 2023-11-07 G. G. Motorina , Yu. T. Tsap , V. V. Smirnova , A. S. Morgachev , A. D. Shramko , A. S. Motorin

In previous works we have developed a method to convert solar X-ray data, collected with the Yohkoh/SXT, into templates of stellar coronal observations. Here we apply the method to several solar flares, for comparison with stellar X-ray…

Astrophysics · Physics 2009-11-06 F. Reale , G. Peres , S. Orlando

The statistical characteristic of stellar flares at optical bands has received an extensive study, but it remains to be studied at soft X-ray bands, in particular for solar-type stars. Here, we present a statistical study of soft X-ray…

Solar and Stellar Astrophysics · Physics 2024-01-19 Zhanhao Zhao , Ziqian Hua , Xin Cheng , Zhiyuan Li , Mingde Ding

We present an analysis of intermittent processes occurred during the impulsive phase of the flare SOL2012-03-13, using hard X-rays and submillimeter radio data. Intermittency is a key characteristic in turbulent plasmas and have been a…

Solar and Stellar Astrophysics · Physics 2016-06-22 C. Guillermo Giménez de Castro , Paulo J. A. Simões , Jean-Pierre Raulin , Odilon M. Guimarães

We propose a new two-stage model for acceleration of electrons in solar flares. In the first stage, electrons are accelerated stochastically in a post-reconnection turbulent downflow. The second stage is the reprocessing of a subset of…

Astrophysics · Physics 2008-11-26 Robert Selkowitz , Eric G. Blackman

We explore the temporal relationship between microwave/HXR emission and Doppler velocity during the impulsive phase of a solar flare on 2014 October 27 (SOL2014-10-27), which displays a pulse on the light curves in microwave (34 GHz) and…

Solar and Stellar Astrophysics · Physics 2017-05-24 Dong Li , Zongjun Ning , Yu Huang , Qingmin Zhang

Oscillations in the solar atmosphere have long been observed in quiet conditions, and increasingly also in data taken during solar flares. The chromosphere is known for its 3-minute signals, which are particularly strong over sunspot…

Solar and Stellar Astrophysics · Physics 2021-03-17 David C. L. Millar , Lyndsay Fletcher , Ryan O. Milligan

We analyzed a highly impulsive solar flare observed on June 3, 2012. In association with this flare, emissions of hard X-rays, high-energy gamma rays, and neutrons were detected by the detectors onboard the FERMI, RHESSI satellites and the…

High Energy Astrophysical Phenomena · Physics 2015-08-21 K. Koga , S. Masuda , H. Matsumoto , Y. Muraki , T. Obara O. Okudaira , S. Shibata , T. Yamamoto , T. Goka

The NOAA listings of solar flares in cycles 21-24, including the GOES soft X-ray magnitudes, enable a simple determination of the number of flares each flaring active region produces over its lifetime. We have studied this measure of flare…

Solar and Stellar Astrophysics · Physics 2014-01-28 Hugh Hudson , Lyndsay Fletcher , Jim McTiernan

When and where the magnetic field energy is released and converted in eruptive solar flares remains an outstanding topic in solar physics. To shed light on this question, here we report multi-wavelength observations of a C9.4-class eruptive…

Solar and Stellar Astrophysics · Physics 2024-03-05 Yuqian Wei , Bin Chen , Sijie Yu , Haimin Wang , Yixian Zhang , Lindsay Glesener

Impulsive 30 THz continuum bursts have been recently observed in solar flares, utilizing small telescopes with a unique and relatively simple optical setup concept. The most intense burst was observed together with a GOES X2 class event on…

Standard model of solar flares comprises a bulk expansion and rise of abruptly heated plasma (the chromospheric evaporation). Emission from plasma ascending along loops rooted on the visible solar disk should be often dominated, at least…

Solar and Stellar Astrophysics · Physics 2009-12-15 R. Falewicz , P. Rudawy , M. Siarkowski

We investigate gamma-ray emission in the impulsive phase of solar flares and the detectability of non-thermal signatures from protostellar flares. Energetic solar flares emit high-energy gamma rays of GeV energies, but their production…

High Energy Astrophysical Phenomena · Physics 2023-03-08 Shigeo S. Kimura , Shinsuke Takasao , Kengo Tomida

Microflares are energetically smaller versions of solar flares, demonstrating the same processes of plasma heating and particle acceleration. However, it remains unclear down to what energy scales this impulsive energy release continues,…

Solar and Stellar Astrophysics · Physics 2024-02-09 Kristopher Cooper , Iain G. Hannah , Lindsay Glesener , Brian W. Grefenstette

The sites of chromospheric excitation during solar flares are marked by extended extreme ultraviolet ribbons and hard X-ray footpoints. The standard interpretation is that these are the result of heating and bremsstrahlung emission from…

Solar and Stellar Astrophysics · Physics 2014-01-28 L. Fletcher , I. G. Hannah , H. S. Hudson , D. E. Innes

The study of the localized plasma conditions before the impulsive phase of a solar flare can help us understand the physical processes that occur leading up to the main flare energy release. Here, we present evidence of a hot X-ray onset…

Solar and Stellar Astrophysics · Physics 2020-12-02 Hugh S. Hudson , Paulo J. A. Simoes , Lyndsay Fletcher , Laura A. Hayes , Iain G. Hannah

We develop a mixed Long Short Term Memory (LSTM) regression model to predict the maximum solar flare intensity within a 24-hour time window 0$\sim$24, 6$\sim$30, 12$\sim$36 and 24$\sim$48 hours ahead of time using 6, 12, 24 and 48 hours of…

Solar and Stellar Astrophysics · Physics 2020-08-26 Zhenbang Jiao , Hu Sun , Xiantong Wang , Ward Manchester , Tamas Gombosi , Alfred Hero , Yang Chen

Spatially-resolved X-ray observations are the key to understanding electron acceleration in solar flares. Currently, the underlying processes that efficiently energize solar flare particles are poorly constrained. Abundant flare…

Solar and Stellar Astrophysics · Physics 2026-03-09 Morgan Stores , Natasha Jeffrey , Ewan Dickson , James McLaughlin , Eduard Kontar

We investigate quasi-periodic pulsations (QPPs) of high-energy nonthermal emissions from an X9.3 flare (SOL2017-Sep-06T11:53), the most powerful flare since the beginning of solar cycle 24. The QPPs are identified as a series of regular and…

Solar and Stellar Astrophysics · Physics 2020-01-15 D. Li , D. Y. Kolotkov , V. M. Nakariakov , L. Lu , Z. J. Ning