AN EXTREME ULTRAVIOLET WAVE ASSOCIATED WITH A MICRO-SIGMOID ERUPTION
Taking advantage of the high temporal and spatial resolution of the Solar Dynamics Observatory (SDO) observations, we present an extreme ultraviolet (EUV) wave associated with a micro-sigmoid eruption on 2010 October 21. The micro-sigmoid underwent a typical 'sigmoid-to-arcade' evolution via tether-cutting reconnection, accompanied by a B1.7 flare, a filament eruption, and coronal twin dimmings. In the eruption, the newly formed sigmoidal loops expanded quickly, and the expansion likely triggered an EUV wave. The wave onset was nearly simultaneous with the start of the eruption and the associated flare. The wave had a nearly circular front and propagated at a constant velocity of 270-350 km s{sup -1} with very little angular dependence. Remarkably, in some direction, the wave encountered a small loop and refracted at a higher speed. All the results provide evidences that the wave was a fast-mode magnetohydrodynamic (MHD) wave. Owing to the close temporal and spatial relationship between the wave and the expanding loops, we believe that the wave was most likely triggered by the fast expansion of the newly formed sigmoidal loops, which evolved into the leading front of the invisible micro-coronal mass ejection.
- OSTI ID:
- 22047696
- Journal Information:
- Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 753; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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