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Prediction of solar flares is an important task in solar physics. The occurrence of solar flares is highly dependent on the structure and the topology of solar magnetic fields. A new method for predicting large (M and X class) flares is…

Solar and Stellar Astrophysics · Physics 2016-12-28 Abbas Raboonik , Hossein Safari , Nasibe Alipour , Michael S. Wheatland

Large solar flares (GOES M-class or higher) are usually associated with eruptions of material. However, when considering flare irradiance enhancements and dynamics such as chromospheric evaporation, potential contributions from erupted…

Solar and Stellar Astrophysics · Physics 2025-12-18 Luke Majury , Marie Dominique , Ryan Milligan , Dana-Camelia Talpeanu , Ingolf Dammasch , David Berghmans

We propose a forecasting approach for solar flares based on data from Solar Cycle 24, taken by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) mission. In particular, we use the Space-weather HMI…

As the Lyman-alpha (Lya) line of neutral hydrogen is the brightest emission line in the solar spectrum, detecting increases in irradiance due to solar flares at this wavelength can be challenging due to the very high background. Previous…

Solar and Stellar Astrophysics · Physics 2021-03-31 Ryan O. Milligan

We consider the flare prediction problem that distinguishes flare-imminent active regions that produce an M- or X-class flare in the future 24 hours, from quiet active regions that do not produce any flare within $\pm 24$ hours. Using…

Solar and Stellar Astrophysics · Physics 2022-06-15 Zeyu Sun , Monica G. Bobra , Xiantong Wang , Yu Wang , Hu Sun , Tamas Gombosi , Yang Chen , Alfred Hero

The Mg II k \& h line intensity ratios can be used to probe the characteristics of the plasma in the solar atmosphere. In this study, using the observations recorded by the Interface Region Imaging Spectrometer (IRIS), we study the…

Solar and Stellar Astrophysics · Physics 2024-03-22 Soumya Roy , Durgesh Tripathi

We analyze the relationship between the flare X-ray peak flux, and characteristics of the Polarity Inversion Line (PIL) and Active Regions (AR), derived from line-of-sight (LOS) magnetograms. The PIL detection algorithm based on a…

Solar and Stellar Astrophysics · Physics 2018-05-29 Viacheslav M Sadykov , Alexander G Kosovichev

In this paper, the cooling of 72 M- and X-class flares is examined using GOES/XRS and SDO/EVE. The observed cooling rates are quantified and the observed total cooling times are compared to the predictions of an analytical 0-D hydrodynamic…

Solar and Stellar Astrophysics · Physics 2014-01-17 Daniel F. Ryan , Phillip C. Chamberlin , Ryan O. Milligan , Peter T. Gallgher

The time evolution of the spectral index and the non-thermal flux in 24 impulsive solar hard X-ray flares of GOES class M was studied in RHESSI observations. The high spectral resolution allows for a clean separation of thermal and…

Astrophysics · Physics 2007-05-23 Paolo C. Grigis , Arnold O. Benz

We present a catalog of 6266 solar flares detected by the X-Ray Solar Monitor onboard the Chandrayaan-2 lunar orbiter between 1.55 and 12.4 keV (1 and 8 \AA) from 2019 September 12 to 2022 November 4, including 1469 type A flares. The…

Aims The possible influence of solar superflares on the near-Earth space radiation environment are assessed through the investigation of scaling laws between the peak proton flux and fluence of Solar Energetic Particle (SEP) events with the…

Solar and Stellar Astrophysics · Physics 2023-03-08 Athanasios Papaioannou , Konstantin Herbst , Tobias Ramm , Edward W. Cliver , David Lario , Astrid M. Veronig

Context: Solar flares release a large fraction of their energy into non-thermal electrons, but it is not clear where and how. Bremsstrahlung X-rays are observed from the corona and chromosphere. Aims: We aim to characterize the acceleration…

Astrophysics · Physics 2009-11-11 Marina Battaglia , Arnold O. Benz

Spatially-resolved X-ray observations are the key to understanding electron acceleration in solar flares. Currently, the underlying processes that efficiently energize solar flare particles are poorly constrained. Abundant flare…

Solar and Stellar Astrophysics · Physics 2026-03-09 Morgan Stores , Natasha Jeffrey , Ewan Dickson , James McLaughlin , Eduard Kontar

The flare activity and the ultraviolet emission of the sun during its 24-th cycle are analysed. As compared to cycles 21-23, where the most powerful flares were observed during the decay phase, in cycle 24 the greatest number of powerful…

Solar and Stellar Astrophysics · Physics 2017-11-29 E. A. Bruevich , G. V. Yakunina

The timing of 503 solar flares observed simultaneously in hard X-rays, soft X-rays and H-alpha is analyzed. We investigated the start and the peak time differences in different wavelengths, as well as the differences between the end of the…

Astrophysics · Physics 2015-06-24 A. Veronig , B. Vrsnak , M. Temmer , A. Hanslmeier

We apply multi-algorithm machine learning models to TESS 2-minute survey data from Sectors 1-72 to identify stellar flares. Models trained with Deep Neural Network, Random Forest, and XGBoost algorithms, respectively, utilized four flare…

Solar and Stellar Astrophysics · Physics 2024-10-24 Chia-Lung Lin , Daniel Apai , Mark S. Giampapa , Wing-Huen Ip

We statistically study the relationship between the Lyman-alpha (\lya) and 1--8 \AA\ soft X-ray (SXR) emissions from 658 M- and X-class solar flares observed by the {\em Geostationary Operational Environmental Satellite} during 2006--2016.…

Solar and Stellar Astrophysics · Physics 2020-11-25 Zhichen Jing , Wuqi Pan , Yukun Yang , Dechao Song , Jun Tian , Y. Li , X. Cheng , Jie Hong , M. D. Ding

Solar flares originate from magnetically active regions but not all solar active regions give rise to a flare. Therefore, the challenge of solar flare prediction benefits by an intelligent computational analysis of physics-based properties…

Solar and Stellar Astrophysics · Physics 2019-10-09 Cristina Campi , Federico Benvenuto , Anna Maria Massone , D Shaun Bloomfield , Manolis K Georgoulis , Michele Piana

Solar flares - bursts of high-energy radiation responsible for severe space-weather effects - are a consequence of the occasional destabilization of magnetic fields rooted in active regions (ARs). The complexity of AR evolution is a barrier…

Solar and Stellar Astrophysics · Physics 2019-05-27 Dattaraj B. Dhuri , Shravan M. Hanasoge , Mark C. M. Cheung

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…