Tracking Solar Energetic Electrons from Corona to 1 AU: A Multi-Spacecraft Study of the 28 January 2025 Event

Abstract

We report and analyze a solar energetic electron (SEE) event on January 28, 2025, associated with an extreme ultraviolet (EUV) jet and accompanied by type III and type II radio bursts. Combining multi-viewpoint in situ and remote-sensing observations with modeling, we trace the propagation of energetic electrons from the corona to interplanetary space across time, space, and energy. Potential Field Source Surface (PFSS) reconstruction shows that coronal type III burst sources and the EUV jet ejection direction generally align with open magnetic field lines. Time Difference of Arrival (TDOA) localization indicates that the interplanetary type III burst source lies along the Parker spiral leading to Wind, with electron-beam velocities of 0.06c – 0.17c. Velocity Dispersion Analysis (VDA) of electrons detected by three spacecraft near 1 AU yields solar release times of 08:03 – 08:23 UT for Solar TErrestrial RElations Observatory-Ahead (STEREO-A) and 08:07 – 08:27 UT for Wind, with derived path lengths of \(1.2 \pm 0.9\) AU and \(2.6 \pm 1.6\) AU, respectively. The path length for Wind exceeds the nominal Parker spiral length, suggesting a complex, non-ideal interplanetary magnetic field topology. This study presents a methodology for tracking SEEs from their source to interplanetary observers, providing observational constraints for space weather forecasting models. We also infer that the locally observed SEEs and the electron beams that excite interplanetary type III bursts may not be the same population, based on differences in their release and arrival times.