Small-scale motions in solar filaments as the precursors of eruptions. (15th April 2019)

• Record Type: Journal Article
• Authors: Seki, Daikichi; Otsuji, Kenichi; Isobe, Hiroaki; Ishii, Takako T; Ichimoto, Kiyoshi; Shibata, Kazunari
• Is Part Of: Publications of the Astronomical Society of Japan. Volume 71:Number 3(2019:Jun.)
• Publication Date: 2019-04-15
• Subjects: methods: statistical -- Sun: coronal mass ejections (CMEs) -- Sun: filaments, prominences -- techniques: image processing -- turbulence; Astronomy -- Periodicals; 520.5
• DOI: 10.1093/pasj/psz031
• Languages: English
• ISSNs: 0004-6264

Abstract

Abstract: Filaments, the dense cooler plasma floating in the solar corona supported by magnetic fields, generally exhibit certain activations before they erupt. In our previous study (Seki et al. 2017, ApJ, 843, L24), we observed that the standard deviation of the line-of-sight (LOS) velocities of the small-scale motions in a filament increased prior to its eruption. However, because that study only analyzed one event, it is unclear whether such an increase in the standard deviation of LOS velocities is common in filament eruptions. In this study, 12 filaments that vanished in Hα line center images were analyzed in a manner similar to the one in our previous work; these included two quiescent filaments, four active region filaments, and six intermediate filaments. We verified that in all the 12 events, the standard deviation of the LOS velocities increased before the filaments vanished. Moreover, we observed that the quiescent filaments had approximately 10 times longer duration of an increase in the standard deviation than the other types of filaments. We concluded that the standard deviation of the LOS velocities of the small-scale motions in a filament can potentially be used as a precursor of a filament eruption.