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The sunspot-associated sources at the frequency of 17 GHz give information on plasma parameters in the regions of magnetic field about B=2000 G at the level of the chromosphere-corona transition region. The observations of short period…

Solar and Stellar Astrophysics · Physics 2015-03-19 Vladimir E. Abramov-Maximov , George B. Gelfreikh , Kiyoto Shibasaki

Three-minute oscillations are a common phenomenon in the solar chromosphere above a sunspot. Oscillations can be affected by the energy release process related to solar flares. In this paper, we report on an enhanced oscillation in flare…

Solar and Stellar Astrophysics · Physics 2023-11-30 Ya Wang , Lyndsay Fletcher , Sargam Mulay , Haisheng Ji , Wenda Cao

We address a possibility of the flare process initiation and further maintenance of its energy release due to a transformation of sunspot longitudinal waves into transverse magnetic loop oscillations with initiation of reconnection. This…

Solar and Stellar Astrophysics · Physics 2015-05-20 R. Sych , M. Karlický , A. Altyntsev , J. Dudík , L. Kashapova

A common feature of electromagnetic emission from solar flares is the presence of intensity pulsations that vary as a function of time. Known as quasi-periodic pulsations (QPPs), these variations in flux appear to include periodic…

Solar and Stellar Astrophysics · Physics 2021-04-14 Brendan P. Clarke , Laura A. Hayes , Peter T. Gallagher , Shane A. Maloney , Eoin P. Carley

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 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

The processes governing energy storage and release in the Sun are both related to the solar magnetic field. We demonstrate the existence of a magnetic connection between energy released caused by a flare and increased oscillatory power in…

Solar and Stellar Astrophysics · Physics 2013-06-17 Aleksandra Andic , R. T. James McAteer

Quasi-periodic pulsations (QPP) are usually found in the light curves of solar and stellar flares, they carry the features of time characteristics and plasma emission of the flaring core, and could be used to diagnose the coronas of the Sun…

Solar and Stellar Astrophysics · Physics 2020-01-08 Ding Yuan , Song Feng , Dong Li , Zhongjun Ning , Baolin Tan

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

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

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 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

Quasi-periodic pulsations (QPPs) are frequently detected in solar and stellar flares, but the underlying physical mechanisms are still to be ascertained. Here, we show microwave QPPs during a solar flare originating from quasi-periodic…

Solar and Stellar Astrophysics · Physics 2022-12-19 Yuankun Kou , Xin Cheng , Yulei Wang , Sijie Yu , Bin Chen , Eduard P. Kontar , Mingde Ding

On 10 March 2001 the active region NOAA 9368 produced an unusually impulsive solar flare in close proximity to the solar limb. This flare has previously been studied in great detail, with observations classifying it as a type 1 white-light…

Astrophysics · Physics 2009-11-13 J. C. Martinez-Oliveros , H. Moradi , A-C. Donea

Quasi-periodic oscillations in solar flaring emission have been observed over the past few decades. To date, the underpinning processes resulting in the quasi-periodic oscillations remain unknown. In this paper, we report a unique event…

Solar and Stellar Astrophysics · Physics 2024-07-08 Yining Zhang , Ting Li , Jing Ye

We studied long duration flare observed with Nobeyama Radioheliograph at frequencies 17 and 34 GHz and with Ramaty High Energy Solar Spectroscopic Imager at 25-50 keV. We found that microwave and hard X-ray emission variation contain…

Solar and Stellar Astrophysics · Physics 2011-10-07 Veronika Reznikova , Kiyoto Shibasaki

We report quasi-periodic pulsations (QPPs) with double periods during three solar flares (viz. SOL2011-Feb-15T01:44, SOL2011-Sep-25T04:31, SOL2012-May-17T01:25). The flare QPPs were observed from light curves in Ly$\alpha$, hard X-ray (HXR)…

Solar and Stellar Astrophysics · Physics 2021-09-08 Lei Lu , Dong Li , Zongjun Ning , Li Feng , Weiqun Gan

We analyze multi-wavelength data of a M7.9/1N class solar flare which occurred on 27 April, 2006 from AR NOAA 10875. GOES soft X-ray images provide the most likely signature of two interacting loops and their reconnection, which triggers…

Solar and Stellar Astrophysics · Physics 2015-05-19 Pankaj Kumar , A. K. Srivastava , B. V. Somov , P. K. Manoharan , R. Erdelyi , Wahab Uddin

We report a solar jet phenomenon associated with successive flares on November 10th 2014. These explosive events were involved with the satellite spots' emergence around a delta-type sunspot in the decaying active region NOAA 12205. The…

Solar and Stellar Astrophysics · Physics 2017-10-11 Takahito Sakaue , Akiko Tei , Ayumi Asai , Satoru Ueno , Kiyoshi Ichimoto , Kazunari Shibata

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
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