Liquid sunshine - Modelling of coronal rain in the quiescent and flaring solar corona

The solar corona, the most extended layer of the solar atmosphere, is home to extremely energetic processes like magnetic reconnection that can dramatically heat up the gas to tens of millions of degrees through the conversion of the Sun's magnetic field energy. This is best exemplified in the solar flare phenomenon, through which enormous amounts of radiation are released in a timescale of minutes to hours and constitute a major hazard for space exploration and telecommunications on Earth.

This extreme energy release process is usually accompanied by an equally strong cooling response from the solar atmosphere, through which a spectacular phenomenon known as coronal rain takes place. Material is seen to catastrophically cool down, generating cold and super dense rain-like clumps that stream along the magnetic field lines.

In this project we aim to quantify for the first time the cooling response to the heating of the solar atmosphere, by conducting state-of-the-art numerical simulations of solar coronal structures subject to multi-scale flaring processes.

Although never quantified, the relation between the energy input and the amount of coronal rain is observed at multiple energetic scales, from the nanoflare energy range at which coronal heating is suspected to operate, to the solar and stellar flare scale. Based on the relatively simple physics involved, scaling laws are expected. Besides the unique diagnostics that coronal rain provides through the dynamics and morphology, such scaling law relation would allow the inference of key unknowns behind quiescent and flare heating of the corona.

Such scaling laws are also relevant for stellar flares, for which tantalising evidence of coronal rain has been found in the spectra but for which the total energy input is poorly quantified.