Do Flares Impact Neighboring Quiescent Coronal Rain?

Solar flares are energetic phenomena that influence coronal plasma dynamics through the magnetic reconnection-driven large-scale reconfiguration, heating and particle acceleration. Even though the energy release is usually strongly localised, it is well known that the flaring can impact a large part of the solar atmosphere through e.g. fast MHD shocks and particle acceleration. Coronal rain is a well known product of strongly stratified heating, seen in quiescent (non-flaring) and flaring conditions. This study investigates quiescent rain showers neighboring a flare site, focusing on their temporal evolution across the pre-flare, impulsive, and gradual phases. Using high-resolution imaging from the Interface Region Imaging Spectrograph (IRIS) and the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO), we perform a quantitative comparison of rain quantity, intensity, and velocity before and after a C7.5 flare. Our results reveal an increase of approximately 27% in the average number of rain events from pre-flare to impulsive phases, suggesting a possible causal link with the flare perturbations. Besides, a significant increase in both average intensity and downflow velocity by 17% and 18%, respectively, from pre-flare to the gradual phases, suggesting a possible flare-induced density enhancement in the neighbouring coronal rain. These findings highlight the potential of using rain as a sensitive indicator of magnetic or thermodynamic changes, primarily governed by internal loop dynamics, but potentially influenced by external, flare-related perturbations.