Work

Are There Local Dynamos Acting in Sunspot Regions?

Year: 2024

Type: article

Abstract: In solar physics, a long-unanswered question is whether or not there are local dynamos acting in sunspot regions. Here we report an observed pattern of magnetic evolution that makes the sunspots alive with ample complexity and energy. This anomalous pattern manifests as peculiar bipolar magnetic emergences (BMEs), exhibiting the following characteristics: (1) the BMEs persistently appear beyond the penumbra, encircling the sunspot in an end-to-end configuration; (2) each BME gradually grows and separates its two polarities along an arc trajectory centered on the sunspot; (3) a circular brightening belt is manifested in the ultraviolet/extreme-ultraviolet radiations during the BMEs’ evolution; and (4) the sunspot regions with such an evolution pattern often exhibit vigorous solar activity, such as homogeneous major flares. The magnetic evolving pattern and relevant flare activity indicate the presence of a local dynamo, and we characterize it as a twisting-reconnecting dynamo.

Source: The Astrophysical Journal

DOI: 10.3847/1538-4357/ad7820

Authors: Chunlan Jin, Guiping Zhou, Haisheng Ji, Jingxiu Wang

Language: English

Topic: Solar and Space Plasma Dynamics

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $4,499

Funders: National Natural Science Foundation of China, National Key Research and Development Program of China

Awards: G3428805212, G7576039942