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Related papers: Study of Solar Active Regions Based on BOAO Vector…

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In this study we combine the multiwavelength ultraviolet -- optical (Solar Dynamics Observatory, SDO) and radio (Nobeyama Radioheliograph, NoRH) observations to get further insight into space-frequency distribution of oscillations at…

Solar and Stellar Astrophysics · Physics 2015-05-13 D. Y. Kolobov , N. I. Kobanov , A. A. Chelpanov , A. A. Kochanov , S. A. Anfinogentov , S. A. Chupin , I. I. Myshyakov , V. E. Tomin

Using a recently proposed nonlinear force-free method designed for single vector magnetograms of solar active regions we calculate the instantaneous free magnetic energy and relative magnetic helicity budgets in 162 vector magnetograms…

Solar and Stellar Astrophysics · Physics 2015-06-11 Kostas Tziotziou , Manolis K. Georgoulis , Nour-Eddine Raouafi

This paper presents a post hoc analysis of a deep learning-based full-disk solar flare prediction model. We used hourly full-disk line-of-sight magnetogram images and selected binary prediction mode to predict the occurrence of…

Machine Learning · Computer Science 2023-10-10 Chetraj Pandey , Rafal A. Angryk , Manolis K. Georgoulis , Berkay Aydin

AD Leo is a young and active M dwarf with high flaring rates across the X-ray to radio bands. Flares accelerate particles in the outer coronal layers and often impact exospace weather. Wide-band radio dynamic spectra let us explore the…

Solar and Stellar Astrophysics · Physics 2024-05-29 Atul Mohan , Surajit Mondal , Sven Wedemeyer , Natchimuthuk Gopalswamy

Solar inter-network magnetic field is the weakest component of solar magnetism, but contributes most of the solar surface magnetic flux. The study on its origin has been constrained by the inadequate tempo-spatial resolution and sensitivity…

Solar and Stellar Astrophysics · Physics 2015-05-26 Chunlan Jin , Jingxiu Wang

In this ISSI-supported series of studies on magnetic helicity in the Sun, we systematically implement different magnetic helicity calculation methods on high-quality solar magnetogram observations. We apply finite-volume, discrete flux tube…

Solar and Stellar Astrophysics · Physics 2021-11-24 J. K. Thalmann , M. K. Georgoulis , Y. Liu , E. Pariat , G. Valori , S. Anfinogentov , F. Chen , Y. Guo , K. Moraitis , S. Yang , A. Mastrano

We study structure and dynamics of the turbulent photospheric magnetic field in the active region NOAA 11158 by characterizing the spatial and temporal scaling properties of the line-of-sight (LOS) component. Using high-resolution…

Solar and Stellar Astrophysics · Physics 2015-06-18 Jordan A. Guerra , Antti A. Pulkkinen , Vadim M. Uritsky , Seiji Yashiro

We analyze data from the Helioseismic Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA) instruments on board the Solar Dynamics Observatory (SDO) to characterize the spatio-temporal acoustic power distribution in active…

Solar and Stellar Astrophysics · Physics 2017-11-06 S. C. Tripathy , K. Jain , S. Kholikov , F. Hill , S. P. Rajaguru , P. S. Cally

Huairou Solar Observing Station of the National Astronomical Observatories of the Chinese Academy of Sciences has been in operation since 1987. Successful observations of the solar vector magnetic field have been conducted during its…

Solar and Stellar Astrophysics · Physics 2025-05-02 Hongqi Zhang , Jiangtao Su , Xiaofan Wang , Xingming Bao , Yu Liu , Yingzi Sun , Mingyu Zhao

We investigate spatio-temporal evolution of high-degree acoustic mode frequencies of the Sun and the surface magnetic activity, over the course of multiple solar cycles, to improve our understanding of the connection between the solar…

Solar and Stellar Astrophysics · Physics 2023-12-20 Mackenzie A. Baird , Sushanta C. Tripathy , Kiran Jain

We analyze the magnetic evolution of solar active region (AR) NOAA 11476 that, between 9 and 10 May 2012, produced a series of surge-type eruptions accompanied by GOES X-ray class M flares. Using force-free models of the AR coronal…

Solar and Stellar Astrophysics · Physics 2024-04-17 Marcelo López Fuentes , Mariano Poisson , Cristina H. Mandrini

The physics of solar flares occurring on the Sun is highly complex and far from fully understood. However, observations show that solar eruptions are associated with the intense kilogauss fields of active regions, where free energies are…

Solar and Stellar Astrophysics · Physics 2024-01-26 Bach Viet Do , Yang Chen , XuanLong Nguyen , Ward Manchester

Sequences of line-of-sight (LOS) magnetograms recorded by the Michelson-Doppler Imager are used to quantitatively characterize photospheric magnetic structure and evolution in three active regions that rotated across the Sun's disk during…

Solar and Stellar Astrophysics · Physics 2015-05-27 B. T. Welsch , S. Christe , J. M. McTiernan

We present a database of 3137 solar flare ribbon events corresponding to every flare of GOES class C1.0 and greater within 45 degrees from the central meridian, from April 2010 until April 2016, observed by the \emph{Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2017-08-23 Maria D. Kazachenko , Benjamin J. Lynch , Brian T. Welsch , Xudong Sun

Observations the Sun's photospheric magnetic field are often confined to the Sun-Earth line. Surface flux transport (SFT) models, such as the Advective Flux Transport (AFT) model, simulate the evolution of the photospheric magnetic field to…

Solar and Stellar Astrophysics · Physics 2024-04-09 Lisa A. Upton , Ignacio Ugarte-Urra , Harry P. Warren , David H. Hathaway

We compute for the first time magnetic helicity and energy spectra of the solar active region NOAA 11158 during 11-15 February 2011 at 20^o southern heliographic latitude using observational photospheric vector magnetograms. We adopt the…

Solar and Stellar Astrophysics · Physics 2014-03-25 Hongqi Zhang , Axel Brandenburg , D. D. Sokoloff

The weak-field approximation implying linear relationship between Stokes $V/I$ and longitudinal magnetic field, $B_{\Vert}$, often suffers from saturation observed in strong magnetic field regions such as sunspot umbra. In this work, we…

Solar and Stellar Astrophysics · Physics 2021-11-22 Andrei Plotnikov , Alexander Kutsenko , Shanbin Yang , Haiqing Xu , Xianyong Bai , Hongqi Zhang , Kirill Kuzanyan

Direct comparison between stellar and solar magnetic maps are hampered by their dramatic differences in resolution. Here, we present a method to filter out the small-scale component of vector fields, in such a way that comparison between…

Solar and Stellar Astrophysics · Physics 2016-04-20 A. A. Vidotto

We present a method for performing data-driven simulations of solar active region formation and evolution. The approach is based on magnetofriction, which evolves the induction equation assuming the plasma velocity is proportional to the…

Solar and Stellar Astrophysics · Physics 2015-06-11 Mark C. M. Cheung , Marc L. DeRosa

We investigated the initiation and the evolution of an X7.1-class solar flare observed in solar active region NOAA 13842 on October 1, 2024, based on a data-constrained magnetohydrodynamic (MHD) simulation. The nonlinear force-free field…

Solar and Stellar Astrophysics · Physics 2025-08-12 Keitarou Matsumoto , Satoshi Inoue , Nian Liu , Keiji Hayashi , Ju Jing , Haimin Wang
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