Poster Abstracts

Name/Affiliation:  Fabio Reale (University of Palermo, Italy)

Title:  The Sun as a template of accretion impacts on young stars

The Sun has recently offered an interesting opportunity to study impacts similar to those of accretion flows from circumstellar disks onto young stars (Reale et al. 2013, Science, 341, 6143, 251). After the eruption of a dense filament triggered by an energetic flare on June 7, 2011 part of the ejected material falls back onto the solar surface. The impact of the downfalling plasma was imaged by the Atmospheric Imaging Assembly (AIA) on-board the Solar Dynamics Observatory (SDO). Hydrodynamic simulations confirm that the high energy emission is produced by the impact of high-density plasma at the highest free-fall speeds and show the importance of the absorption in reducing the X-ray emission and of fragmentation in explaining the line broadenings. Impacts such as these present a laboratory for stellar astronomers to study the impact of dense (accreting) circumstellar material in unique detail.