Speaker
Description
First Name: Athanasios
Last Name: Papaioannou
Affiliation: National Observatory of Athens
All Authors: Athanasios Papaioannou, Laura Rodríguez-García, Raúl Gómez-Herrero, Eleni Lavasa, Athanasios Kouloumvakos, George Vasalos, Alexander Warmuth, Ian G. Richardson, David Lario, Ioannis Zouganelis, Bernd Heber, Marlon Köberle, Manon Jarry, Monica Laurenza, Francisco Espinosa Lara, Ignacio Cernuda, Patrick Kühl, Jan Gieseler, Christian Palmroos, Frederic Schuller, Krzysztof Barczynski, Sebastian Fleth, Anastasios Anastasiadis, Andrew Walsh, Daniel Müller, Javier Rodríguez-Pacheco, Robert F. Wimmer-Schweingruber, Rami Vainio, and Alexis P. Rouillard
Abstract: We present a catalogue of Solar Energetic Particle (SEP) events observed by the High Energy Telescope (HET) of the Energetic Particle Detector (EPD) suite on Solar Orbiter during the ascending and peak phases of Solar Cycle 25 (2020–2025). Using parallel surveys of relativistic electrons (~1 MeV) and protons (~8 MeV, including events with >25 and >50 MeV protons), we identified enhancements above background and derived key properties such as onset and peak times, peak fluxes, fluences, and electron-to-proton ratios. The catalogue contains 212 high-energy SEP events. For each event, the SEP release times were estimated using time-shifting and velocity-dispersion analyses (VDA) and compared with flare observations to identify parent solar sources and associated Coronal Mass Ejections (CMEs). Solar wind magnetic field and plasma measurements were used to contextualize each event, and connection angles were calculated to assess magnetic connectivity of the spacecraft to the source. We examined how SEP characteristics relate to flare and CME parameters and explored the diagnostic value of e/p ratios and elemental abundances for distinguishing impulsive and gradual SEP events. As part of this work, we developed open-source tools—SEP-PACT for catalogue construction and VDA for release-time analysis—available through the SPEARHEAD (SPEcification, Analysis & Re-calibration of High Energy pArticle Data) GitHub repository [https://github.com/spearhead-he]. The catalogue will be released via Zenodo and the SPEARHEAD web interface [https://spearhead-he.eu].