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Related papers: The slow magnetoacoustic mode in the flaring loop

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We present simultaneous X-ray and spectral ultraviolet (UV) observations of strikingly-coherent oscillations in emission from a coronal looptop and fan structure, during the impulsive phase of a long-duration M-class solar flare. The 50 s…

Solar and Stellar Astrophysics · Physics 2024-11-06 Ryan J. French , Laura A. Hayes , Maria D. Kazachenko , Katharine K. Reeves , Chengcai Shen , Juraj Lörinčík

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

High time resolution observations of a white--light flare on the active star EQ PegB show evidence of intensity variations with a period of approximately 10 s. The period drifts to longer values during the decay phase of the flare. If the…

Astrophysics · Physics 2009-11-11 M. Mathioudakis , D. S. Bloomfield , D. B. Jess , V. S. Dhillon , T. R. Marsh

Rapidly decaying long-period oscillations often occur in hot coronal loops of active regions associated with small (or micro-) flares. This kind of wave activity was first discovered with the SOHO/SUMER spectrometer from Doppler velocity…

Solar and Stellar Astrophysics · Physics 2021-10-01 Tongjiang Wang , Leon Ofman , Ding Yuan , Fabio Reale , Dmitrii Y. Kolotkov , Abhishek K. Srivastava

We investigate the solar flare of 20 October 2002. The flare was accompanied by quasi-periodic pulsations (QPP) of both thermal and nonthermal hard X-ray emissions (HXR) observed by RHESSI in the 3-50 keV energy range. Analysis of the HXR…

Solar and Stellar Astrophysics · Physics 2015-05-14 I. V. Zimovets , A. B. Struminsky

We present a multiwavelength analysis of the long duration flare observed on 15 April 2002 (soft X-ray peak time at 03:55 UT, SOL2002-04-15T03:55). This flare occurred on the disk (S15W01) in NOAA 9906 and was observed by a number of space…

Solar and Stellar Astrophysics · Physics 2020-03-11 A. Kepa , B. Sylwester , J. Sylwester , T. Mrozek , M. Siarkowski

We present the first X-ray observation of an oscillation during a stellar flare. The flare occurred on the active M-type dwarf AT Mic and was observed with XMM-Newton. The soft X-ray light curve (0.2-12 keV) is investigated with wavelet…

Astrophysics · Physics 2007-05-23 U. Mitra-Kraev , L. K. Harra , D. R. Williams , E. Kraev

The analysis of narrowband drifting of type III-like structures in radio bursts dynamic spectra allows to obtain unique information about primary energy release mechanisms in solar flares. The SSRT spatially resolved images and a high…

Solar and Stellar Astrophysics · Physics 2015-06-05 N. S. Meshalkina , A. T. Altyntsev , D. A. Zhdanov , S. V. Lesovoi , A. A. Kochanov , Yan Yihua , Tan Chengming

We found systematic microwave source motions along a flare-arcade using Nobeyama Radioheliograph (NoRH) 17 GHz images. The motions were associated with a X-class disk flare which occurred on 15th February 2011. For this study, we also used…

Solar and Stellar Astrophysics · Physics 2015-06-17 Sujin Kim , Kiyoto Shibasaki , Satoshi Masuda

We report for the first time the detection of thermal free-free emission from post-flare loops at 34GHz in images from the Nobeyama Radioheliograph (NoRH). We studied 8 loops, 7 of which were from regions with extremely strong coronal…

Solar and Stellar Astrophysics · Physics 2024-06-24 Costas E. Alissandrakis , Gregory D. Fleishman , Viktor V. Fedenev , Stephen M. White , Alexander T. Altyntsev

We observe intensity oscillations along coronal fan loops associated with the active region AR 11428. The intensity oscillations were triggered by blast waves which were generated due to X-class flares in the distant active region AR 11429.…

Solar and Stellar Astrophysics · Physics 2017-09-20 V. Pant , A. Tiwari , D. Yuan , D. Banerjee

We present multi-wavelength observations by Chandrayaan-2/XSM, SDO/AIA and Hinode/XRT of a B-class flare observed on 25th February, 2021, originating from an active region (AR 12804) near the North-West limb. The microflare lasts for approx…

Solar and Stellar Astrophysics · Physics 2023-08-30 Yamini K. Rao , B. Mondal , Giulio Del Zanna , N. P. S. Mithun , S. V. Vadawale , K. K. Reeves , Helen E. Mason , Anil Bhardwaj

Solar small scale microwave bursts (SMBs), including microwave dot, spike, and narrow band type III bursts, are characterized with very short timescales, narrow frequency bandwidth, and very high brightness temperatures. Based on…

Solar and Stellar Astrophysics · Physics 2015-06-16 Baolin Tan

Low-frequency longitudinal oscillations of a flaring coronal loop are studied numerically. In the recent work of Nakariakov et al., Astron. and Astrophys., 414, L25-L28 (2004) it has been shown that the time dependences of density and…

Astrophysics · Physics 2009-11-10 D. Tsiklauri , V. M. Nakariakov , T. D. Arber , M. J. Aschwanden

We studied the characteristic physical properties and behavior of broadband microwave sub-second pulsations observed in an expanding coronal loop during the GOES C2.4 solar flare on 2011 August 10. We found sub-second pulsations and other…

Solar and Stellar Astrophysics · Physics 2016-09-28 Hana Meszarosova , Jan Rybak , Larisa Kashapova , Peter Gomory , Susanna Tokhchukova , Ivan Myshyakov

We describe microwave and hard X-ray observations of strong quasiperiodic pulsations from the GOES X1.3 solar flare on 15 June 2003. The radio observations were made jointly by the Owens Valley Solar Array (OVSA), the Nobeyama Polarimeter…

Astrophysics · Physics 2009-11-13 G. D. Fleishman , T. S. Bastian , D. E. Gary

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

We explored the quasi-periodic pulsations (QPPs) at multiple periods during an X4.0 flare on 2024 May 10 (SOL2024-05-10T06:27), which occurred in the complex active region of NOAA 13664. The flare radiation reveals five prominent periods in…

Solar and Stellar Astrophysics · Physics 2025-04-14 Dong Li , Ding Yuan , Jingye Yan , Xinhua Zhao , Zhao Wu , Jincheng Wang , Zhenyong Hou , Chuan Li , Haisheng Zhao , Libo Fu , Lin Wu , Li Deng

Quasi-periodic oscillations of the hard X-ray (HXR) emission of the large flare of 2 November 1991 have been investigated using HXR light curves and soft X-ray and HXR images recorded by the {\sl Yohkoh} X-ray telescopes. The results of the…

Solar and Stellar Astrophysics · Physics 2015-06-15 Jerzy Jakimiec , Michal Tomczak

Observational detection of quasi-periodic drifting fine structures in a type III radio burst associated with a solar flare SOL2015-04-16T11:22, with Low Frequency Array, is presented. Although similar modulations of the type III emission…

Solar and Stellar Astrophysics · Physics 2018-07-11 Dmitrii Y. Kolotkov , Valery M. Nakariakov , Eduard P. Kontar