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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

It is well known that the long-term evolution of the photospheric magnetic field plays an important role in building up free energy to power solar eruptions. Observations, despite being controversial, have also revealed a rapid and…

Solar and Stellar Astrophysics · Physics 2012-09-11 Shuo Wang , Chang Liu , Rui Liu , Na Deng , Yang Liu , Haimin Wang

Since May 1, 2010, we have been able to study (almost) continuously the vector magnetic field in the Sun, thanks to two space-based observatories: the Solar Dynamics Observatory (SDO) and Hinode. Both are equipped with instruments able to…

Solar and Stellar Astrophysics · Physics 2018-01-24 Alberto Sainz Dalda

Solar activity can be witnessed in the form of sunspots and active regions, where the magnetic field is enhanced by up to a factor 1000 as compared to that of the quiet Sun. In addition, solar activity manifests itself in terms of flares,…

Solar and Stellar Astrophysics · Physics 2025-07-25 Gottfried Mann , Frédéric Schuller

Solar flares are caused by magnetic eruptions in active regions (ARs) on the surface of the sun. These events can have significant impacts on human activity, many of which can be mitigated with enough advance warning from good forecasts. To…

Solar and Stellar Astrophysics · Physics 2023-09-18 Varad Deshmukh , Thomas Berger , James Meiss , Elizabeth Bradley

Solar flares and coronal mass ejections (CMEs), especially the larger ones, emanate from active regions (ARs). With the aim to understand the magnetic properties that govern such flares and eruptions, we systematically survey all flare…

Solar and Stellar Astrophysics · Physics 2017-01-11 Shin Toriumi , Carolus J. Schrijver , Louise K. Harra , Hugh Hudson , Kaori Nagashima

In this work, we examine the association between solar active regions and 152 solar flares, coronal mass ejections, and solar energetic particle (SEP) events over solar cycles 23-24 (1997-2017). The CDAW center's GOES data in the energy…

Solar and Stellar Astrophysics · Physics 2025-04-21 Raj Kumar , Ramesh Chandra , Bimal Pande , Seema Pande

Solar active regions (ARs) that produce major flares typically exhibit strong plasma shear flows around photospheric magnetic polarity inversion lines (MPILs). It is therefore important to quantitatively measure such photospheric shear…

Solar and Stellar Astrophysics · Physics 2018-10-29 Sung-Hong Park , Jordan A. Guerra , Peter T. Gallagher , Manolis K. Georgoulis , D. Shaun Bloomfield

Large scale solar eruptions significantly impact space weather and damages space-based human infrastructures. It is necessary to predict large scale solar eruptions, which will enable us to protect our vulnerable infrastructures of modern…

Solar and Stellar Astrophysics · Physics 2020-07-08 Soumitra Hazra , Gopal Sardar , Partha Choudhuri

Solar flares, especially the M- and X-class flares, are often associated with coronal mass ejections (CMEs). They are the most important sources of space weather effects, that can severely impact the near-Earth environment. Thus it is…

Solar and Stellar Astrophysics · Physics 2022-12-02 Hewei Zhang , Qin Li , Yanxing Yang , Ju Jing , Jason T. L. Wang , Haimin Wang , Zuofeng Shang

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

State-of-the-art solar instrumentation is revealing magnetic activity of the Sun with unprecedented resolution. Observations with the 1.6m New Solar Telescope of the Big Bear Solar Observatory are making next steps in our understanding of…

Solar and Stellar Astrophysics · Physics 2015-06-19 Santiago Vargas Dominguez , Alexander Kosovichev , Vasyl Yurchyshyn

We study flare processes in the lower solar atmosphere using observational data for a M1-class flare of June 12, 2014, obtained by New Solar Telescope (NST/BBSO) and Helioseismic Magnetic Imager (HMI/SDO). The main goal is to understand…

Solar and Stellar Astrophysics · Physics 2016-04-20 I. N. Sharykin , V. M. Sadykov , A. G. Kosovichev , S. Vargas-Dominguez , I. V. Zimovets

Strong solar magnetic fields are the energy source of intense flares and energetic coronal mass ejections of space weather importance. The key issue is the difficulty in predicting the occurrence time and location of strong solar eruptions,…

Solar and Stellar Astrophysics · Physics 2023-07-04 P. K. Manoharan , C. J. Salter , S. M. White , P. Perillat , F. Fernandez , B. Perera , A. Venkataraman , C. Brum

On 2024 May 10/11, the strongest geomagnetic storm since November 2003 has occurred, with a peak Dst index of -412 nT. The storm was caused by NOAA Active Region (AR) 13664, which was the source of a large number of coronal mass ejections…

Solar and Stellar Astrophysics · Physics 2024-09-13 Robert Jarolim , Astrid Veronig , Stefan Purkhart , Peijin Zhang , Matthias Rempel

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

Solar active regions (ARs) are the places hosting the majority of solar eruptions. Studying the evolution and morphological features of ARs is not only of great significance to the understanding of the physical mechanisms of solar…

Solar and Stellar Astrophysics · Physics 2025-02-26 Ruishuo Chen , Wutong Lu , Qi Hao , Yifan Meng , Pengfei Chen , Chenxi Shi

We present a radiative magnetohydrodynamics simulation of the formation of an Active Region on the solar surface. The simulation models the rise of a buoyant magnetic flux bundle from a depth of 7.5 Mm in the convection zone up into the…

Solar and Stellar Astrophysics · Physics 2015-05-19 M. C. M. Cheung , M. Rempel , A. M. Title , M. Schüssler

With multiple vantage points around the Sun, STEREO and SDO imaging observations provide a unique opportunity to view the solar surface continuously. We use He II 304 A data from these observatories to isolate and track ten active regions…

Solar and Stellar Astrophysics · Physics 2015-12-16 Ignacio Ugarte-Urra , Lisa Upton , Harry P. Warren , David H. Hathaway

Large-scale velocity fields in the solar photosphere remain a mystery in spite of many years of intensive studies. In this thesis, the new method of the measurements of the solar photospheric flow fields is proposed. It is based on local…

Astrophysics · Physics 2007-12-13 Michal Svanda