STRW local: Regular Colloquia


PROMINENT: unraveling the secrets ofsolar prominences and coronal rain showers

Date: 28-11-2019
Time: 11:15 h
Author: Rony Keppens

In theERC-funded project PROMINENT, we set forth to study the `coolest'part of the million-degree solar atmosphere: the condensations formed by thermal instabilities. These come in all shapes and sizes, with the largest condensations forming prominences -clouds suspended magnetically against gravity, one hundredfold cooler and denser than the atmosphere itself. Their formation, internal dynamics, and ultimate ejection into violent coronal mass ejections are routinely witnessed with modern solar observatories,but they pose severechallenges to modelling efforts. I will present state-of-the-art magnetohydrodynamic simulations, where the process of runaway condensations due to radiative losses is studied in unprecedented detail. The simulations cover prominence scenarios as well as coronal rain showers, where small-scale condensations repeatedly form and rain down in thermodynamically structured magnetic arcades.This solar analog of our own weather turns out to be ubiquitous throughout the solar atmosphere. Our simulations all use the open-source MPI-AMRVAC simulation toolkit [1,2], where the grid-adaptivity is essential to zoom in on details that will be resolved byfuture observing facilities.[1][2] Keppens et al., 2012, JCP 231, 718; Porth et al., 2014, ApJS 214, 4