Filamentary Structures Formation around a Magnetic Pore Using High-resolution Observations of the Goode Solar Telescope

Abstract

With the aid of high-resolution spatial and temporal observations from the Goode Solar Telescope, we present an investigation of the emergence, coalescence, and submergence of a moving magnetic feature (MMF) in the region surrounding a magnetic pore located at the periphery of a large sunspot. The results show that the MMF has a magnetic field strength greater than 500 G and is dominated by the horizontal magnetic component. We observe upflow at the inner part and downflow at the outer part, indicating a pattern of Evershed flow. The MMF emergence is accompanied by the expansion of a granule, which has several striations inside just like the twisted features found in the penumbra filament. Our analysis shows that although these striations have different properties of magnetic field and kinematics during the expansion of the granule, the overall magnetic and dynamic properties of the MMF remain stable. We find that the region where the MMF emerges and submerges becomes more penumbra-like, i.e., adjacent positive and negative values of elongated magnetic features that are parallel to each other, while the optical penumbra-like features are not apparent at the same time. Our work indicates that the dynamics of the MMF near the magnetic pore is important for the development of filamentary structure. The magnetic configuration produced by an MMF together with the elongation of a granule could thus be key to understand the formation of penumbra filaments.

Keywords

• Sunspots
• Solar magnetic fields
• Solar photosphere