7705 20260105160132.0 POSTER-2026-0013 Patel, Ritesh Unprecedented Fine Structures in Coronal Flare Ribbons Revealed by Solar Orbiter's High-Resolution Imager 2025 2025-06-08 We present unprecedented observations of fine substructures within a flare ribbon in the solar corona. During its perihelion on September 30, 2024, Solar Orbiter observed a M7.7-class flare using its suite of instruments from a distance of 0.29 AU. We analyze the physical properties of small-scale downflowing features embedded within the flare ribbons. These structures have widths on the order of a few hundred kilometers, making them among the smallest features identified during magnetic reconnection in the solar corona. The downflows exhibit velocities ranging from 30 to 100 km/s, while the corresponding flare ribbon—along with the embedded substructures—moved laterally at approximately 5.3 km/s, increasing more than threefold as the flare progressed. This acceleration coincided with enhanced X-ray emission observed by STIX. Notably, the presence of relatively cool plasma (~1 MK) within the downflowing features during the flare's rise phase provides new insights into the complex dynamics of magnetic reconnection in the solar atmosphere. STCE Solar Orbiter EUI flare Molnar, Momchil Singh, Prakhar Pant, Vaibhav Seaton, Daniel Caspi, Amir Hassler, Don Berghmans, David 246th Meeting of the American Astronomical Society, Anchorage/Alaska david.berghmans@ksb-orb.be https://ui.adsabs.harvard.edu/abs/2025AAS...24630711P/abstract https://aas.org/meetings/aas246/program CPOSTER