Two Episodes of Magnetic Reconnections during a Confined Circular-ribbon Flare

	Two Episodes of Magnetic Reconnections during a Confined Circular-ribbon Flare
	Li, Ting; Yang, Shuhong; Zhang, Qingmin; Hou, Yijun; Zhang, Jun
刊名	ASTROPHYSICAL JOURNAL
	2018
卷号	859 期号:2 页码:122
英文摘要	We analyze a unique event with an M1.8 confined circular-ribbon flare on 2016 February 13, with successive formations of two circular ribbons at the same location. The flare had two distinct phases of UV and extreme ultraviolet emissions with an interval of about 270 s, of which the second peak was energetically more important. The first episode was accompanied by the eruption of a mini-filament and the fast elongation motion of a thin circular ribbon (CR1) along the counterclockwise direction at a speed of about 220 km s(-1). Two elongated spinerelated ribbons were also observed, with the inner ribbon co-temporal with CR1 and the remote brightenings forming similar to 20 s later. In the second episode, another mini-filament erupted and formed a blowout jet. The second circular ribbon and two spine-related ribbons showed similar elongation motions with that during the first episode. The extrapolated three-dimensional coronal magnetic fields reveal the existence of a fan-spine topology, together with a quasi-separatrix layer (QSL) halo surrounding the fan plane and another QSL structure outlining the inner spine. We suggest that continuous null-point reconnection between the filament and ambient open field occurs in each episode, leading to the sequential opening of the filament and significant shifts of the fan plane footprint. For the first time, we propose a compound eruption model of circular-ribbon flares consisting of two sets of successively formed ribbons and eruptions of multiple filaments in a fan-spine-type magnetic configuration.
语种	英语
WOS记录号	WOS:000433938500021
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/18054]
专题	中国科学院紫金山天文台
推荐引用方式 GB/T 7714	Li, Ting,Yang, Shuhong,Zhang, Qingmin,et al. Two Episodes of Magnetic Reconnections during a Confined Circular-ribbon Flare[J]. ASTROPHYSICAL JOURNAL,2018,859(2):122.
APA	Li, Ting,Yang, Shuhong,Zhang, Qingmin,Hou, Yijun,&Zhang, Jun.(2018).Two Episodes of Magnetic Reconnections during a Confined Circular-ribbon Flare.ASTROPHYSICAL JOURNAL,859(2),122.
MLA	Li, Ting,et al."Two Episodes of Magnetic Reconnections during a Confined Circular-ribbon Flare".ASTROPHYSICAL JOURNAL 859.2(2018):122.