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Previous analyses of magnetospheric accretion and outflow in classical T Tauri stars (CTTSs), within the context of both the X-wind model and other theoretical scenarios, have assumed a dipolar geometry for the stellar magnetic field if it…

Astrophysics · Physics 2009-11-13 Subhanjoy Mohanty , Frank H. Shu

The most probable initial magnetic configuration of a CME is a flux rope consisting of twisted field lines which fill the whole volume of a dark coronal cavity. The flux ropes can be in stable equilibrium in the coronal magnetic field for…

Solar and Stellar Astrophysics · Physics 2015-06-23 Boris Filippov , Olesya Martsenyuk , Abhishek K. Srivastava , Wahab Uddin

Solar flares and coronal mass ejections (CMEs) are closely coupled through magnetic reconnection. CMEs are usually accelerated impulsively within the low solar corona, synchronized with the impulsive flare energy release. We investigate the…

The strength of the radial component of the interplanetary magnetic field (IMF), which is a measure of the Sun's total open flux, is observed to vary by roughly a factor of two over the 11 yr solar cycle. Several recent studies have…

Solar and Stellar Astrophysics · Physics 2021-04-16 Y. -M. Wang , N. R. Sheeley

We study dynamics of relativistic Coronal Mass Ejections (CMEs), from launching by shearing of foot-points (either slowly - the ``Solar flare'' paradigm, or suddenly - the ``star quake" paradigm), to propagation in the preceding magnetar…

High Energy Astrophysical Phenomena · Physics 2023-08-14 Praveen Sharma , Maxim Barkov , Maxim Lyutikov

On the Sun, the energetic, erupting phenomena of flares and coronal mass ejections (CMEs) often occur together. While space-based photometry has revealed frequent white-light flares for vast numbers of stars, only a handful of coronal mass…

Solar and Stellar Astrophysics · Physics 2024-07-17 K. Vida , B. Seli , R. M. Roettenbacher , A. Görgei , L. Kriskovics , Zs. Kővári , K. Oláh

Solar CMEs and flares have a statistically well defined relation, with more energetic X-ray flares corresponding to faster and more massive CMEs. How this relation extends to more magnetically active stars is a subject of open research.…

Magnetism defines the complex and dynamic solar corona. Coronal mass ejections (CMEs) are thought to be caused by stresses, twists, and tangles in coronal magnetic fields that build up energy and ultimately erupt, hurling plasma into…

We demonstrate that for weak flares the dependence on spottedness can be rather weak. The fact is that such flares can occur both in small and large active regions. At the same time, powerful large flares of classes M and X occur much more…

Solar and Stellar Astrophysics · Physics 2022-09-07 M. M. Katsova , V. N. Obridko , D. D. Sokoloff , I. M. Livshits

Solar flares and coronal mass ejections (CMEs) are the most powerful explosions in the Sun. They are major sources of potentially destructive space weather conditions. However, the possible causes of their initiation remain controversial.…

Solar and Stellar Astrophysics · Physics 2017-08-16 X. L. Yan , C. W. Jiang , Z. K. Xue , J. C. Wang , E. R. Priest , L. H. Yang , D. F. Kong , W. D. Cao , H. S. Ji

The magnetic fields of young stars set their coronal properties and control their spin evolution via the star-disc interaction and outflows. Using 14 magnetic maps of 10 classical T Tauri stars (CTTSs) we investigate their closed X-ray…

Solar and Stellar Astrophysics · Physics 2015-06-17 C. P. Johnstone , M. Jardine , S. G. Gregory , J. -F. Donati , G. Hussain

Solar coronal mass ejections (CMEs) are large-scale eruptions of plasma and magnetic field from the Sun into the corona and interplanetary space. They are the most significant drivers of adverse space weather at Earth and other locations in…

Solar and Stellar Astrophysics · Physics 2012-02-20 Jason P. Byrne

Coronal mass ejections (CMEs) are the most spectacular eruptive phenomena in the solar atmosphere. It is generally accepted that CMEs are results of eruptions of magnetic flux ropes (MFRs). However, a heated debate is on whether MFRs…

Solar and Stellar Astrophysics · Physics 2015-06-22 Hongqiang Song , Jie Zhang , Yao Chen , Xin Cheng

Owing to our dependance on spaceborne technology, an awareness of disturbances in the near-Earth space environment is proving to be increasingly crucial. Earth-directed Coronal mass ejections (CMEs) emanating from the Sun are the primary…

Solar and Stellar Astrophysics · Physics 2014-07-17 Arun Babu

Context: Many previous studies have shown that the magnetic precursor of a coronal mass ejection (CME) takes the form of a magnetic flux rope, and a subset of them have become known as `hot flux ropes' due to their emission signatures in…

Solar and Stellar Astrophysics · Physics 2021-01-04 Alexander W James , Lucie M Green , Lidia van Driel-Gesztelyi , Gherardo Valori

Solar flares and coronal mass ejections (CMEs), the most catastrophic eruptions in our solar system, have been known to affect terrestrial environments and infrastructure. However, because their triggering mechanism is still not…

Solar and Stellar Astrophysics · Physics 2015-06-11 K. Kusano , Y. Bamba , T. T. Yamamoto , Y. Iida , S. Toriumi , A. Asai

In our own solar system, the necessity of understanding space weather is readily evident. Fortunately for Earth, our nearest stellar neighbor is relatively quiet, exhibiting activity levels several orders of magnitude lower than young,…

Solar and Stellar Astrophysics · Physics 2016-11-25 Alicia Aarnio , Keivan Stassun , Sean Matt

Large-scale solar eruptions often include ejection of a filament, a solar flare, and expulsion of a coronal mass ejection (CME). Unravelling the magnetic processes that build up the free energy for these eruptions and trigger that energy's…

Solar and Stellar Astrophysics · Physics 2024-10-03 Alphonse C. Sterling , Ronald L. Moore , Navdeep K. Panesar

Coronal mass ejections (CMEs) are the eruptions of magnetised plasma from the Sun and are considered the main driver of adverse space weather events. Hence, undrstanding its formation process, particularly the magnetic topology, is critical…

Solar and Stellar Astrophysics · Physics 2025-02-26 Jinhan Guo , Y. W. Ni , B. Schmieder , Y. Guo , C. Xia , P. Devi , R. Chandra , S. Poedts , R. Joshi , Y. H. Zhou , H. T. Li , P. F. Chen

Current coronal mass ejection (CME) models set their lower boundary to be in the lower corona. They do not calculate accurately the transfer of free magnetic energy from the convection zone to the magnetically dominated corona because they…

Solar and Stellar Astrophysics · Physics 2015-05-19 James E. Leake , Mark G. Linton , Spiro K. Antiochos