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Related papers: Soft X-ray Pulsations in Solar Flares

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We present a case study of the solar flare (SOL2001-10-02T17:31) that showed quasi-periodic pulsations (QPPs) in hard X-rays with two simultaneously excited periods, P_1 = 26-31 s and P_2 = 110 s. Complete evolution of the flare recorded by…

Solar and Stellar Astrophysics · Physics 2014-12-09 M. Tomczak , Z. Szaforz

Electromagnetic (radio, visible-light, UV, EUV, X-ray and gamma-ray) emission generated by solar and stellar flares often contains pronounced quasi-periodic pulsations (QPP). Physical mechanisms responsible for the generation of long-period…

Solar and Stellar Astrophysics · Physics 2015-05-20 V. M. Nakariakov , A. R. Inglis , I. V. Zimovets , C. Foullon , E. Verwichte , R. Sych , I. N. Myagkova

Flares close to the solar limb, where the footpoints are occulted, can reveal the spectrum and structure of the coronal loop-top source in X-rays. We aim at studying the properties of the corresponding energetic electrons near their…

We report observations of quasi-periodic pulsations (QPPs) during the X2.2 flare of 2011 February 15, observed simultaneously in several wavebands. We focus on fluctuations on time scale 1-30 s and find different time lags between different…

Quasi-periodic pulsations (QPPs), which carry time features and plasma characteristics of flare emissions, are frequently observed in light curves of solar/stellar flares. In this paper, we investigated non-stationary QPPs associated with…

Solar and Stellar Astrophysics · Physics 2022-09-23 Dong Li , Fanpeng Shi , Haisheng Zhao , Shaolin Xiong , Liming Song , Wenxi Peng , Xinqiao Li , Wei Chen , Zongjun Ning

We present a statistical analysis of properties of Soft X-Ray (SXR) emission, plasma temperature (T), and emission measure (EM), derived from GOES observations of flares in 2002-2017. The temperature and emission measures are obtained using…

Solar and Stellar Astrophysics · Physics 2019-03-27 Viacheslav M Sadykov , Alexander G Kosovichev , Irina N Kitiashvili , Alexander Frolov

We have performed a search for flares and Quasi-Periodic Pulsations (QPPs) from low mass M dwarf stars using TESS 2 min cadence data. We find seven stars which show evidence of QPPs. Using Fourier and Empirical Mode Decomposition…

Solar and Stellar Astrophysics · Physics 2021-11-17 Gavin Ramsay , Dmitrii Kolotkov , J. Gerry Doyle , Lauren Doyle

We present the first multi-wavelength simultaneous detection of QPP in a superflare (more than a thousand times stronger than known solar flares) on a cool star, in soft X-rays (SXR, with XMM-Newton) and white light (WL, with Kepler). It…

Solar and Stellar Astrophysics · Physics 2022-01-05 Dmitrii Y. Kolotkov , Valery M. Nakariakov , Robin Holt , Alexey A. Kuznetsov

The robust detection of quasi-periodic pulsations (QPPs) in solar and stellar flares has been the topic of recent debate. In light of this, we have adapted a method described by Vaughan (2005) to aid with the search for QPPs in flare time…

Solar and Stellar Astrophysics · Physics 2017-06-07 C. E. Pugh , A. -M. Broomhall , V. M. Nakariakov

Solar flare X-ray emission results from rapidly increasing temperatures and emission measures in flaring active region loops. To date, observations from the X-Ray Sensor (XRS) onboard the Geostationary Operational Environmental Satellite…

Solar and Stellar Astrophysics · Physics 2013-03-07 Daniel F. Ryan , Ryan O. Milligan , Peter T. Gallagher , Brian R. Dennis , A. Kim Tolbert , Richard A. Schwartz , C. Alex Young

Solar flares with a fan-spine magnetic topology can form circular ribbons. The previous study based on H\alpha line observations of the solar flares during March 05, 2014 by Xu et al. (2017) revealed uniform and continuous rotation of the…

Solar and Stellar Astrophysics · Physics 2020-10-21 L. K. Kashapova , E. G. Kupriyanova , Z. Xu , H. A. S. Reid , D. Y. Kolotkov

There are relatively few observations of UV emission during the impulsive phases of solar flares, so the nature of that emission is poorly known. Photons produced by solar flares can resonantly scatter off atoms and ions in the corona.…

Solar and Stellar Astrophysics · Physics 2015-05-28 H. Johnson , J. C. Raymond , N. A. Murphy , S. Giordano , Y. -K. Ko , A. Ciaravella , R. Suleiman

Quasi-periodic pulsations (QPPs) with various periods that originate in the underlying magnetohydrodynamic processes of the flaring structures are detected repeatedly in the solar flare emissions. We apply a 2D cellular automaton (CA)…

Solar and Stellar Astrophysics · Physics 2022-09-14 Nastaran Farhang , Farhad Shahbazi , Hossein Safari

Context. Quasi-periodic pulsations (QPPs) are an inherent feature of solar and stellar flares. However, the mechanism behind them is debated hence it is necessary to further study them to obtain a complete picture of flares and their…

Solar and Stellar Astrophysics · Physics 2025-08-20 Aadish Joshi , Tom Van Doorsselaere , Daye Lim , Dario J. Fritzewski

Solar flares are complex phenomena emitting all types of electromagnetic radiation, and accelerating particles on timescales of minutes, converting magnetic energy to thermal, radiative, and kinetic energy through magnetic reconnections. As…

Solar and Stellar Astrophysics · Physics 2023-09-01 Crisel Suarez , Christopher S. Moore

Mercury mission MESSENGER's %(MErcury Surface, Space ENvironment, GEochemistry, and Ranging Solar Assembly for X-rays (SAX) observed almost 700 solar flares between May 28, 2007 and August 19, 2013, as cataloged by…

Solar and Stellar Astrophysics · Physics 2021-01-06 Erica Lastufka , Säm Krucker

Quasi-periodic pulsations (QPPs) in the Balmer continuum of solar white-light flares (WLFs) are rarely reported, and accurately pinpointing the spatial source of flaring QPPs remains a significant challenge. We present spatiotemporal…

Power-law frequency distributions of the peak flux of solar flare X-ray emission have been studied extensively and attributed to a system of self-organized criticality (SOC). In this paper, we first show that, so long as the shape of the…

Solar and Stellar Astrophysics · Physics 2016-10-12 You-ping Li , Li Feng , Ping Zhang , Siming Liu , Weiqun Gan

In this paper, the energy budgets of two single-loop like flares observed in X- ray are analysed under the assumption that non-thermal electrons (NTEs) are the only source of plasma heating during all phases of both events. The flares were…

Solar and Stellar Astrophysics · Physics 2014-06-19 R. Falewicz

An peculiar microwave quasi-periodic pulsation (QPP) accompanying with a hard X-ray (HXR) QPP of about 20 s duration occurred just before the maximum of an X6.9 solar flare on 2011 August 9. The most interesting is that the microwave QPP is…

Solar and Stellar Astrophysics · Physics 2015-06-04 Baolin Tan , Chengming Tan