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arXiv · 2610.35677

Connectivity rewiring and filament formation by active region emergence observed with Solar Orbiter

Xiaohong Li·Sami K. Solanki·Thomas Wiegelmann·Gherardo Valori·Daniele Calchetti·Johann Hirzberger·Clara Froment·Henrik Eklund·Nicolas Poirier·Luc Rouppe van der Voort·Elias R. Udnæs·Joachim Woch·Achim Gandorfer
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Abstract

Using an 11-day dataset from Solar Orbiter, combining EUV imaging, H$α$ observations, vector magnetograms and nonlinear force-free field extrapolations, we track the evolution from the emergence of a new active region to the reconfiguration of coronal connectivity. We find that the restructuring proceeds through a sequence of localized reconnection events that propagate along the filament channel, producing successive brightenings and bidirectional flows. This process leads to the gradual erosion of the original filament and the simultaneous formation of a new, highly sheared filament connecting the two regions. Magnetic modeling reveals a transition from a sheared arcade supporting the initial filament to a twisted flux rope underlying the newly formed structure. Our results demonstrate that flux emergence can reorganize filament channels through a spatially and temporally ordered sequence of reconnection events, rather than a single impulsive episode. This sequential reconnection front provides a natural mechanism for filament formation in evolving active regions and highlights the importance of continuously changing magnetic connectivity in the corona.

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Xiaohong Li, Sami K. Solanki, Thomas Wiegelmann, Gherardo Valori, Daniele Calchetti, Johann Hirzberger, Clara Froment, Henrik Eklund, Nicolas Poirier, Luc Rouppe van der Voort, Elias R. Udnæs, Joachim Woch, Achim Gandorfer. 2026-10-26. Connectivity rewiring and filament formation by active region emergence observed with Solar Orbiter. https://arxiv.org/abs/2610.35677

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