In this article, we present a multi-wavelength investigation of a C-class flaring activity that occurred in the active region NOAA 12734 on 8 March 2019. The investigation utilizes data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) and the Udaipur-CALLISTO solar radio spectrograph of the Physical Research Laboratory. This low intensity C1.3 event is characterized by typical features of a long-duration event (LDE), viz. extended flare arcade, large-scale two-ribbon structures and twin coronal dimmings. The eruptive event occurred in a coronal sigmoid and displayed two distinct stages of energy release, manifested in terms of temporal and spatial evolution. The formation of twin-dimming regions are consistent with the eruption of a large flux rope with footpoints lying in the western and eastern edges of the coronal sigmoid. The metric radio observations obtained from Udaipur-CALLISTO reveals a broad-band (\(\approx50\,\text{--}\,180~\text{MHz}\)), stationary plasma emission for \(\approx7~\text{min}\) during the second stage of the flaring activity that resemble a type IV radio burst. A type III decametre-hectometre radio bursts with starting frequency of \(\approx2.5~\text{MHz}\) precedes the stationary type IV burst observed by Udaipur-CALLISTO by \(\approx5~\text{min}\). The synthesis of multi-wavelength observations and non-linear force-free field (NLFFF) coronal modeling together with magnetic decay index analysis suggest that the sigmoid flux rope underwent a zipping-like uprooting from its western to eastern footpoints in response to the overlying asymmetric magnetic field confinement. The asymmetrical eruption of the flux rope also accounts for the observed large-scale structures viz. apparent eastward shift of flare ribbons and post-flare loops along the polarity inversion line (PIL), and provides evidence for lateral progression of magnetic reconnection site as the eruption proceeds.

在本文中，我们对 2019 年 3 月 8 日在活动区域​​ NOAA 12734 中发生的 C 级耀斑活动进行了多波长调查。该调查利用来自大气成像组件 (AIA) 和日震磁成像仪 (HMI) 的数据) 在太阳动力学天文台 (SDO) 和物理研究实验室的 Udaipur-CALLISTO 太阳射电光谱仪上。这种低强度 C1.3 事件的特点是长持续时间事件 (LDE) 的典型特征，即。扩展的耀斑拱廊、大型两条带状结构和双日冕调光。喷发事件发生在日冕 sigmoid 中，并表现出两个不同的能量释放阶段，表现在时间和空间演化方面。双调光区的形成与一条大通量绳的喷发一致，其脚点位于日冕乙状结肠的西部和东部边缘。从 Udaipur-CALLISTO 获得的公制无线电观测揭示了一个宽带（\(\approx50\,\text{--}\,180~\text{MHz}\) )，在燃烧活动的第二阶段，\(\approx7~\text{min}\) 的稳态等离子体发射类似于 IV 型射电暴。起始频率为\(\approx2.5~\text{MHz}\) 的III 型十米-百米射电暴先于 Udaipur-CALLISTO 观测到的固定 IV 型爆发\(\approx5~\text{min}\). 多波长观测和非线性无力场 (NLFFF) 日冕建模以及磁衰变指数分析的综合表明，S 形磁通绳从其西到东的脚点经历了一个像拉链一样的连根拔起，以响应上覆的不对称磁场约束。通量绳的不对称喷发也解释了观察到的大型结构，即。耀斑带和耀斑后环沿极性反转线 (PIL) 的明显东移，并为随着火山喷发进行磁重联位点的横向进展提供了证据。