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Related papers: Solar Flare Effects on the Earth's Lower Ionospher…

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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

Aims: This paper aims to demonstrate the importance of short-exposure extreme ultraviolet (EUV) observations of solar flares in the study of particle acceleration, heating and energy partition in flares. This work highlights the…

We recently presented evidence of a strong correlation between the energy in the high-frequency part of the acoustic spectrum of the Sun and the solar X-ray flux Karoff & Kjeldsen (2008). The discovery indicates that flares drive global…

Astrophysics · Physics 2008-10-17 C. Karoff

A major flare (of class X3.4) occurred on 13 December 2006 in the active region NOAA 10930. The energy released during flares is also known to induce acoustic oscillations in the Sun. Here, we analyze the line-of-sight velocity patterns in…

Solar and Stellar Astrophysics · Physics 2015-06-03 Brajesh Kumar , P. Venkatakrishnan , Savita Mathur , Sanjiv Kumar Tiwari , R. A. Garcia

The Earth's ionosphere introduces systematic effects that limit the performance of a radio interferometer at low frequencies ($\lesssim 1$\,GHz). These effects become more pronounced for severe geomagnetic activities or observations…

Earth and Planetary Astrophysics · Physics 2023-02-02 Sarvesh Mangla , Sumanjit Chakraborty , Abhirup Datta , Ashik Paul

On October 3rd, 2024, the Sun emitted an X9.0-class flare from active region NOAA 13842. The event was recorded by multiple space-based instruments, beginning hours before the eruption, granting a unique opportunity to provide insight into…

Solar and Stellar Astrophysics · Physics 2026-05-28 Louis Seyfritz , Maria Kazachenko , Ryan French

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

The paper presents results of a search for helioseismic events (sunquakes) produced by M-X class solar flares during Solar Cycle 24. The search is performed by analyzing photospheric Dopplergrams from Helioseismic Magnetic Imager (HMI).…

Solar and Stellar Astrophysics · Physics 2020-06-03 I. N. Sharykin , A. G. Kosovichev

We present a detailed analysis of a C9.3 white-light flare using high-resolution observations from the New Vacuum Solar Telescope (NVST). The flare occurred near the eastern solar limb on September 11, 2023, within NOAA AR 13431, and…

Solar and Stellar Astrophysics · Physics 2025-06-11 Zhe Xu , Xiaoli Yan , Zhentong Li , Liheng Yang , Zhike Xue , Jincheng Wang , Yian Zhou

We have used Transition Region and Coronal Explorer (TRACE) 1600 \AA images and Global Oscillation Network Group (GONG) magnetograms to compare ultraviolet (UV) emissions from the chromosphere to longitudinal magnetic field changes in the…

Solar and Stellar Astrophysics · Physics 2012-11-12 Brittany Johnstone , Gordon Petrie , Jeffrey Sudol

In this paper, we analyzed a number of problems that are relevant for the physics of solar-terrestrial relationships and the dynamics of geospheres. It is shown that permanent 5-minute oscillations of the photosphere, well known in…

Geophysics · Physics 2018-08-17 A. V. Guglielmi , A. S. Potapov

Using Gaussian process methods, we analyzed the light curves of three extreme solar X-ray flares observed by the RHESSI satellite. Their variability characteristics were then compared with those of HXMT-HE X-ray burst (XRB; in SGR…

High Energy Astrophysical Phenomena · Physics 2025-12-15 Haiyun Zhang , Dahai Yan , Lijuan Dong , Ping Zhang , Ruijing Tang , Jianeng Zhou , Lian Tao , Li Zhang , Niansheng Tang

The solar flare on July 30, 2011 was of a modest X-ray class (M9.3), but it made a strong photospheric impact and produced a "sunquake," observed with the Helioseismic and Magnetic Imager (HMI) on NASA's Solar Dynamics Observatory (SDO). In…

Solar and Stellar Astrophysics · Physics 2015-08-06 I. N. Sharykin , A. G. Kosovichev

We use Renewal Theory for the estimation and interpretation of the flare rate from the Geostationary Operational Environmental Satellite (GOES) soft X-ray flare catalogue. It is found, that in addition to the flare rate variability with the…

Solar and Stellar Astrophysics · Physics 2015-03-20 Andrei Gorobets , Mauro Messerotti

We report high-resolution observations at mid-infrared wavelengths of a minor solar flare, SOL2014-09-24T17T17:50 (C7.0), using Quantum Well Infrared Photodetector (QWIP) cameras at an auxiliary of the McMath-Pierce telescope. The flare…

Solar and Stellar Astrophysics · Physics 2016-03-23 M Penn , S Krucker , H Hudson , M Jhabvala , D Jennings , A Lunsford , P Kaufmann

This short paper reviews several recent key observations of the processes occurring in the lower atmosphere (chromosphere and photosphere) during flares. These are: evidence for compact and fragmentary structure in the flare chromosphere,…

Solar and Stellar Astrophysics · Physics 2013-12-02 Lyndsay Fletcher , Paulo J. A. Simoes

The extreme ultraviolet portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include…

Solar and Stellar Astrophysics · Physics 2015-09-16 Ryan O. Milligan

Ground- and space-based observations of solar flares from radio wavelengths to gamma-rays have produced considerable insights but raised several unsolved controversies. The last unexplored wavelength frontier for solar flares is in the…

Solar flares often happen after a preflare / preheating phase, which is almost or entirely thermal. In contrast, there are the so-called early impulsive flares that do not show a (significant) preflare heating but instead often show the…

Solar and Stellar Astrophysics · Physics 2018-04-04 Alexandra L. Lysenko , Alexander T. Altyntsev , Natalia S. Meshalkina , Dmitriy Zhdanov , Gregory D. Fleishman

Solar flares, along with other sun-originated events such as Coronal Mass Ejections, fast solar wind streams, and solar energetic particles are among the most relevant events in Space Weather. Moreover, solar flares are the most energetic…

Solar and Stellar Astrophysics · Physics 2022-11-21 Nicola Plutino , Francesco Berrilli , Dario Del Moro , Luca Giovannelli