Abundance variations and first ionization potential trends during large stellar flares

Abundance variations and first ionization potential trends during large stellar flares

Context. The Solar First Ionization Potential (FIP) effect, where low-FIP (FIP <∼10 eV) elements are enriched in the corona relative to the photosphere, while high-FIP abundances remain unchanged, has been known for a long while. High resolution X-ray spectroscopy has revealed that active stellar coronae show an opposite effect, which was labeled the Inverse-FIP (IFIP) effect. The correlation f...

Nucleosynthesis in stellar flares

Nuclear interactions of ions accelerated at the surface of flaring stars can produce fresh isotopes in stellar atmospheres. Although this nucleosynthesis is not significant for the chemical evolution of the Galaxy, it can be important for a number of measurements of “anomalously” high Li and Li abundances. We discuss the possible role of stellar flares to explain the recent report of high Li ab...

Modeling Solar and Stellar Flares

Stellar Flares and Coronal Structure

Coronal structure and coronal heating are intimately related in magnetically active stars. Coronal structure is commonly inferred from radio interferometry and from eclipse and rotational modulation studies. We discuss to what extent flares may be responsible for coronal structure and global observable properties in magnetically active stars.

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...