Patel, Ritesh ; Molnar, Momchil ; Singh, Prakhar ; Pant, Vaibhav ; Seaton, Daniel ; Caspi, Amir ; Hassler, Don ; Berghmans, David

Poster presented at 246th Meeting of the American Astronomical Society, Anchorage/Alaska on 2025-06-08

Abstract: 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.

Keyword(s): Solar Orbiter ; EUI ; flare
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