Document Type
Article
Publication Date
12-1-2025
Department
Department of Engineering Physics
School or Division
Graduate School of Engineering and Management
Digital Object Identifier
Source Publication
The Astrophysical Journal (ISSN 0004-637X | eISSN 1538-4357)
Abstract
The study of solar active regions (ARs) is of central importance to a range of fundamental science, as well as the practical applications of space weather. Active region emergence and life cycles are two areas of particular interest, yet the lack of consistent full-Sun observations has made long-term studies of active regions difficult. Here, we present results from a study to identify and characterize long-lived active regions (LLARs), defined as those which were observed during at least two consecutive Carrington rotations and which did not undergo significant successive flux emergence once the decay phase began. Such active regions accounted for 13% of all NOAA-identified ARs between 2011 and 2019, and their distribution closely follows the annual sunspot number. This implies that LLARs are produced by the same basic driving processes as regular ARs. LLAR areas tend to be significantly larger and contain more magnetic flux compared to other ARs, but the two categories have similar magnetic complexity distributions. The most striking result, however, is that LLARs are 3-6 times more likely than other ARs to be the source of a solar flare of GOES class C or greater. This highlights the importance of studying what makes a LLAR and how to identify them at emergence with a view towards improved space weather forecasting. The further implications of these findings for AR heating spatial and temporal patterns will be explored in an upcoming study.
Recommended Citation
Mason, E. I., & Kniezewski, K. L. (2025). Statistical Overview of Long-lived Active Regions Observed across Multiple Carrington Rotations. The Astrophysical Journal, 994(2), 208. https://doi.org/10.3847/1538-4357/ae197d
Comments
© 2025 The Authors.
This article is published by The Institute of Physics (IOP), licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
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This record on AFIT Scholar previously directed readers to the arXiv manuscript of the article before it was published. http://arxiv.org/abs/2510.24924