Resolving interchange reconnection dynamics in a fan-spine-like topology observed by Solar Orbiter

¹ Yunnan Observatories, Chinese Academy of Sciences Kunming 650216, China
² Yunnan Key Laboratory of Solar Physics and Space Science Kunming 650216, PR China
³ School of Earth and Space Sciences, Peking University Beijing 100871, PR China
⁴ School of Physics and Astronomy, Yunnan University Kunming 650500, China
⁵ Centre for Mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven Celestijnenlaan 200B bus 2400 B-3001 Leuven, Belgium
⁶ Leibniz Institute for Astrophysics Potsdam An der Sternwarte 16 Potsdam 14482, Germany

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Received: 9 September 2025
Accepted: 30 November 2025

Abstract

Interchange reconnection is thought to play a significant role in the production of solar jets and the solar wind. The dynamics of interchange reconnection in the low corona might be more complex than recognized before in higher temporal and spatial resolutions, however. Using unprecedentedly high-resolution observations from the Extreme Ultraviolet Imager (EUI) on board the Solar Orbiter, we analyzed the dynamics of interchange reconnection in a small-scale fan-spine-like topology. The interchange reconnection that continuously occurs around the multinull points of the fan-spine-like system exhibits a quasi-periodicity of ∼200 s that nearly covers the entire evolution of this system. Continuous evolution and a reversal of multiple current sheets are observed over time near the null point. These results reveal that the dynamics of interchange reconnection is likely modulated by emerging magnetic structures, such as mini-filaments and emerging arcades. Moreover, a curtain-like feature with a width of 1.7 Mm is also observed near the interchange reconnection region and persistently generates outflows. This is similar to the separatrix curtain reported in the pseudostreamer structure. This study not only demonstrates the complex and variable reconnection dynamics of interchange reconnection within a small-scale fan-spine topology, but also provides insights into the self-similarity of magnetic field configurations across multiple temporal and spatial scales.