Speaker
Description
First Name: Luke
Last Name: Majury
Email Address: lmajury01@qub.ac.uk
Affiliation: Queen's University Belfast
All Authors: Luke Majury, Marie Dominique, Ryan Milligan, Dana-Camelia Talpeanu, Ingolf Dammasch, David Berghmans
Abstract: While the majority of large magnitude flares (GOES M-class and above) are associated with eruptions of material, the excess irradiance from this material has yet to be quantified. We analyse a sample of ten eruptive M- and X-class flares observed during 2024 and 2025, employing a masking technique to separate the irradiance enhancements from eruption and ribbon sources as observed by SDO/AIA. For four of these events, imaging analysis of HXR data from SolO/STIX and ASO-S/HXI was performed to assess the importance of nonthermal particle heating within the eruptions. The sample-averaged percentages of excess radiated energy by erupted material over the flares' impulsive phases were 10%, 24%, 21% and 13% for the 131 Å, 171 Å, 304 Å and 1600 Å channels, respectively. We find that these eruptions did not show ubiquitous signatures of nonthermal heating, lacking consistent spatial overlap between HXR sources and the erupted material. One event was jointly observed at the solar limb by HXI and STIX at ~170 degrees of separation, with HXR spectroscopy providing insights into differences in nonthermal electron properties at varying atmospheric heights. The observed irradiance contributions from eruptions likely drive spectral variability that may be misinterpreted as signatures of chromospheric evaporation and successful CMEs, particularly in Sun-as-a-star and stellar observations. Further analysis of spatially resolved spectral data from existing instruments such as IRIS and Hinode/EIS, and upcoming instruments such as MUSE and SOLAR-C, may elucidate the role of eruptions in this spectral variability. Additionally, such data may clarify whether turbulent energy release, inferred through nonthermal line broadening, can drive the observed irradiance enhancements.