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Related papers: Pre-Flare Dynamics of Sunspot Groups

200 papers

Here, we test the weighted horizontal magnetic gradient ($WG_M$) as a flare precursor, introduced by Korsos et. al. (2015, ApJ, 802, L21), by applying it to a magneto-hydrodynamic (MHD) simulation of solar-like flares Chatterjee et. al.…

Solar and Stellar Astrophysics · Physics 2018-04-30 M. B. Korsos , Piyali Chatterjee , R. Erdelyi

Solar flares commonly have a hot onset precursor event" (HOPE), detectable from soft X-ray observations. Detecting this requires subtraction of pre-flare fluxes from the non-flaring Sun prior to the event, fitting an isothermal emission…

Solar and Stellar Astrophysics · Physics 2024-07-08 Hugh S. Hudson

Solar active regions (ARs) that produce strong flares and coronal mass ejections (CMEs) are known to have a relatively high non-potentiality and are characterized by delta-sunspots and sheared magnetic structures. In this study, we conduct…

Solar and Stellar Astrophysics · Physics 2017-11-29 Shin Toriumi , Shinsuke Takasao

In this dataset we provide a comprehensive collection of magnetograms (images quantifying the strength of the magnetic field) from the National Aeronautics and Space Administration's (NASA's) Solar Dynamics Observatory (SDO). The dataset…

Solar and Stellar Astrophysics · Physics 2024-02-13 Laura E. Boucheron , Ty Vincent , Jeremy A. Grajeda , Ellery Wuest

The accurate forecasting of solar flares is considered a key goal within the solar physics and space weather communities. There is significant potential for flare prediction to be improved by incorporating topological fluxes of magnetogram…

Solar and Stellar Astrophysics · Physics 2024-12-06 Thomas Williams , Christopher B. Prior , David MacTaggart

In this study, the non-potential magnetic field parameters of active region NOAA 9077 are investigated; this AR experienced a super-strong X5.7 solar flare. Using advanced extrapolation techniques, the 3D magnetic field structure from…

Solar and Stellar Astrophysics · Physics 2025-06-18 Liu Suo , Shahid Idrees , Liu Dian , Zeng Shuguang

In this paper, we present a multi-wavelength analysis of an eruptive white-light M3.2 flare which occurred in active region NOAA 10486 on November 1, 2003. Excellent set of high resolution observations made by RHESSI and TRACE provide clear…

Solar and Stellar Astrophysics · Physics 2015-05-30 Bhuwan Joshi , Astrid M. Veronig , Jeongwoo Lee , Su-Chan Bong , Sanjiv K. Tiwari , Kyung-Suk Cho

The R-value is a measure of the strength of photospheric magnetic Polarity Inversion Lines (PILs) in Active Regions (ARs). This work investigates the possibility of a relation between R-value variations and the occurrence of X-class flares…

Using the data on magnetic field maps and continuum intensity for Solar Cycles 23 and 24, we explored 100 active regions (ARs) that produced M5.0 or stronger flares. We focus on the presence/absence of the emergence of magnetic flux in…

Solar and Stellar Astrophysics · Physics 2024-02-29 Alexander S. Kutsenko , Valentina I. Abramenko , Andrei A. Plotnikov

Solar flares emanate from solar active regions hosting complex and strong bipolar magnetic fluxes. Estimating the probability of an active region to flare and defining reliable precursors of intense flares is an extremely challenging task…

Intermittent magnetohydrodynamical turbulence is most likely at work in the magnetized solar atmosphere. As a result, an array of scaling and multi-scaling image-processing techniques can be used to measure the expected self-organization of…

Astrophysics · Physics 2007-05-23 Manolis K. Georgoulis

Solar flares are known to generate seismic waves in the Sun. We present a detailed analysis of seismic emission in sunspots accompanying M- and X-class solar flares. For this purpose, we have used high-resolution Dopplergrams and…

Solar and Stellar Astrophysics · Physics 2020-07-13 Hirdesh Kumar , Brajesh Kumar

A time series of GONG Dopplergrams for the period 10-14 May 1997 from Udaipur and Big Bear sites has been used to measure the velocity fluctuations in the sunspot (NOAA active region 8038) and quiet photosphere simultaneously. We observe…

Astrophysics · Physics 2015-06-24 Brajesh Kumar , R. Jain , S. C. Tripathy , Hari Om Vats , M. R. Deshpande

We study the photospheric magnetic field of ~2000 active regions in solar cycle 23 to search for parameters indicative of energy build-up and subsequent release as a solar flare. We extract three sets of parameters: snapshots in space and…

Solar and Stellar Astrophysics · Physics 2015-07-01 Amani Al-Ghraibah , Laura. E. Boucheron , R. T. James McAteer

Current operational forecasts of solar eruptions are made by human experts using a combination of qualitative shape-based classification systems and historical data about flaring frequencies. In the past decade, there has been a great deal…

Solar and Stellar Astrophysics · Physics 2020-06-02 V. Deshmukh , T. E. Berger , E. Bradley , J. D. Meiss

We quantify the emergence and decay rates of preceder (p) and follower (f) sunspots within ten active regions from 2010-2014 using Space-weather Helioseismic Magnetic Imager Active Region Patch data. The sunspots are small- to mid-sized…

Solar and Stellar Astrophysics · Physics 2017-06-21 A. A. Norton , E. H. Jones , M. G. Linton , J. E. Leake

We have investigated the variation of magnetic helicity over a span of several days around the times of 11 X-class flares which occurred in seven active regions (NOAA 9672, 10030, 10314, 10486, 10564, 10696, and 10720) using the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Sung-Hong Park , Jeongwoo Lee , Gwang-Son Choe , Jongchul Chae , Hyewon Jeong , Guo Yang , Ju Jing , Haimin Wang

The subsurface properties of active regions prior to their appearance at the solar surface may shed light on the process of active region formation. Helioseismic holography has been applied to samples taken from two populations of regions…

Solar and Stellar Astrophysics · Physics 2016-08-24 G. Barnes , A. C. Birch , K. D. Leka , D. C. Braun

We investigated four major solar flare events that occurred in active regions NOAA 10930 (December 13 and 14, 2006) and NOAA 11158 (February 13 and 15, 2011) by using data observed by the Solar Optical Telescope (SOT) onboard the Hinode…

Solar and Stellar Astrophysics · Physics 2015-06-17 Y. Bamba , K. Kusano , T. T. Yamamoto , T. J. Okamoto

The review addresses the spatial frequency morphology of sources of sunspot oscillations and waves, including their localization, size, oscillation periods, height localization with the mechanism of cut-off frequency that forms the observed…

Solar and Stellar Astrophysics · Physics 2016-03-09 Robert Sych