Physical Processes During Impulsive Solar and Stellar Flares

Modeling Solar and Stellar Flares

Scaling Laws of Solar and Stellar Flares

In this study we compile for the first time comprehensive data sets of solar and stellar flare parameters, including flare peak temperatures Tp, flare peak volume emission measures EMp, and flare durations τf from both solar and stellar data, as well as flare length scales L from solar data. Key results are that both the solar and stellar data are consistent with a common scaling law of EMp ∝ T...

The gas - dynamic model of impulsive stellar flares

We investigate the response of a plasma in a magnetically confined loop to intense impulsive energy release during stellar flares. We carry out a numerical simulation of gas-dynamic processes in an approximation to a single-fluid, two-temperature, plasma with a possible distinction between the ion and electron temperatures taken into account. We present here results of the modelling for an init...

Transition Region Emission and Energy Input to Thermal Plasma During the Impulsive Phase of Solar Flares

The energy released in a solar flare is partitioned between thermal and nonthermal particle energy and lost to thermal conduction and radiation over a broad range of wavelengths. It is difficult to determine the conductive losses and the energy radiated at transition region temperatures during the impulsive phases of flares. We use UVCS measurements of O VI photons produced by 5 flares and subs...

He IN IMPULSIVE SOLAR FLARES BY ELECTRON FIREHOSE WAVES

A new mechanism for acceleration and enrichment of He during impulsive solar flares is presented. Low-frequency electromagnetic plasma waves excited by the Electron Firehose Instability (EFI) can account for the acceleration of ions up to 1 MeV amu energies as a single stage process. The EFI arises as a direct consequence of the free energy stored in a temperature anisotropy (T e ‖ > T e ⊥) of ...