Observing the release of twist by magnetic reconnection in a solar filament eruption.
Magnetic reconnection is a fundamental process of topology change and energy release, taking place in plasmas on the Sun, in space, in astrophysical objects and in the laboratory. However, observational evidence has been relatively rare and typically only partial. Here we present evidence of fast reconnection in a solar filament eruption using high-resolution H-alpha images from the New Vacuum Solar Telescope, supplemented by extreme ultraviolet observations. The reconnection is seen to occur between a set of ambient chromospheric fibrils and the filament itself. This allows for the relaxation of magnetic tension in the filament by an untwisting motion, demonstrating a flux rope structure. The topology change and untwisting are also found through nonlinear force-free field modelling of the active region in combination with magnetohydrodynamic simulation. These results demonstrate a new role for reconnection in solar eruptions: the release of magnetic twist.
Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650216, China.|Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China.
Zhike
Z
Xue
Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650216, China.
Xiaoli
X
Yan
School of Astronomy and Space Science, Nanjing University, Nanjing, Jiangsu 210093, China.
Xin
0000-0003-2837-7136
X
Cheng
Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650216, China.|Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China.
Liheng
L
Yang
Key Laboratory for Dark Matter and Space Science, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, Jiangsu 210008, China.
Yingna
Y
Su
Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650216, China.|Institute of Physics and Astronomy, University of Potsdam, Potsdam 14476, Germany.
Bernhard
B
Kliem
Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China.
Jun
J
Zhang
Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650216, China.
Zhong
Z
Liu
Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650216, China.
Yi
Y
Bi
Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650216, China.
Yongyuan
Y
Xiang
School of Astronomy and Space Science, Nanjing University, Nanjing, Jiangsu 210093, China.
Kai
K
Yang
Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan 650216, China.
Li
L
Zhao