Related papers: Solar-type Magnetic Reconnection Model for Magneta…
Solar flares and coronal mass ejections are among the most prominent manifestations of the magnetic activity of the Sun. The strongest events of them tend to occur in active regions (ARs) that are large, complex, and dynamically evolving.…
The activity of magnetars is believed to be powered by colossal magnetic energy reservoirs. We sketch an evolutionary picture in which internal field evolution in magnetars generates a twisted corona, form which energy may be released…
Solar eruptions are the most powerful drivers of space weather. To understand their cause and nature, it is crucial to know how the coronal magnetic field evolves before eruption. Here we study the formation process of a relatively…
Solar flare ribbons, manifesting as transient brightenings in the chromosphere, are believed to trace out the footpoints of magnetic field lines that are reconnecting higher in the solar atmosphere. These field lines lie in a separatrix or…
Magnetic reconnection is a fundamental process in a laboratory, magnetospheric, solar and astrophysical plasma, whereby magnetic energy is converted into heat, bulk kinetic energy and fast particle energy. Its nature in two dimensions is…
Soft gamma-ray repeaters (SGRs) are mainly a Galactic population and originate from neutron stars with intense ($B\simeq 10^{15}{\rm \ G}$) magnetic fields ('magnetars'). Occasionally, a giant flare occurs with enormous intensity,…
Transient X-ray emission, with an approximate t^{-0.7} decay, was observed from SGR 1900+14 over 40 days following the the giant flare of 27 Aug 1998. We calculate in detail the diffusion of heat to the surface of a neutron star through an…
The evolution of an X2.7 solar flare, that occurred in a complex $\beta\gamma\delta$ magnetic configuration region on 2003 November 3 is discussed utilizing a multi-wavelength data set. The very first signature of pre-flare coronal activity…
Solar active regions and the processes that occur in them have been extensively studied and analyzed and many types of models and characterizations have been proposed for the occurrence of different eruptive events that take place in the…
Recent data on superflares on sun-like stars and radiocarbon data on solar activity in the past are both indicative of transient epochs of unusually high magnetic activity. We propose an explanation for the grand activity maxima in the…
Magnetar Giant Flares (MGFs) are the most energetic non-catastrophic transients known to originate from stellar objects. The first discovered events were nearby. In recent years, several extragalactic events have been identified, implying…
Magnetic free energy powers solar flares and coronal mass ejections (CMEs), and the buildup of magnetic helicity might play a role in the development of unstable structures that subsequently erupt. To better understand the roles of energy…
Solar flares - which are the most prominent manifestation of the solar activity - typically manifest themselves as a single or a set of luminous arcs (magnetic flux tubes) rooted in regions of opposite polarity in the photosphere. However,…
The 'standard solar' flare model collects all physical ingredients identified by multi-wavelength observations of our Sun: magnetic reconnection, fast particle acceleration and the resulting emission at various wavelengths, especially in…
The emission from Sgr A*, the supermassive black hole in the Galactic Center, shows order of magnitude variability ("flares") a few times a day that is particularly prominent in the near-infrared (NIR) and X-rays. We present a…
The contemporary multi-wavelength observations have revealed various important features during solar flares which, on one hand, support the two-dimensional (2D) "standard flare model" while, on other hand, also urge for the exploration of…
I consider a model of GRBs where they arise right before the merging of binary pulsars. Binary pulsars moving through the companion's magnetic field experience a large, motional electric field $\vec{E}=\vec{v}\wedge\vec{B}/c$, which leads…
n order to better understand the solar genesis of interplanetary magnetic clouds (MCs) we model the magnetic and topological properties of four large eruptive solar flares and relate them to observations. We use the three-dimensional…
Stellar flares with ${10^2-10^7}$ times more energy than the largest solar flare have been detected from 9 normal F and G main sequence stars (Schaefer, King & Deliyannis 1999). These superflares have durations of hours to days and are…
Magnetic reconnection is a well-accepted part of the theory of solar eruptive events, though the evidence is still circumstantial. Intrinsic to the reconnection picture of a solar eruptive event, particularly in the standard model for…