The Origin of a Preeruptive Magnetic Structure with Significant Nonneutralized Electric Current

• DOI: 10.3847/1538-4357/adb7d8
• Publication Date: 2025-03-24T06:38:33Z
• Authors: Wensi Wang; Rui Liu; Jiong Qiu; Jinhan Guo; Yuming Wang
• Keywords: Electric current

Abstract The buildup of the preeruptive magnetic field configuration and eruption onset mechanism are critical yet poorly understood in solar eruptions. Coronal structures like sigmoids filaments have been identified as structures; their associated preflare motions well brightenings precursor signatures, none these definitively lead to eruptions, cause effect is contentious. Most importantly, how coronal structure evolves with photospheric elusive. Here we report development nonneutralized electric current a observed bundle hot low-lying loops collectively taking sigmoidal shape. significant appeared several hours ahead formation structure. corona was simultaneous gradual extension photosphere. synchronous evolution seemed stop when intermittent brightening occurred along corona. lasted for about 4 hr, two ribbon-like matching current. Eventually, evolved into flux rope (MFR) erupted. Quantitative measurements indicate that also flows through footpoints erupting MFR, which by pair conjugate dimmings. demonstrated signal imminent eruption.