Simultaneous Horizontal and Vertical Oscillation of a Quiescent Filament Observed by CHASE and SDO

Abstract

In this paper, we present the imaging and spectroscopic observations of the simultaneous horizontal and vertical large-amplitude oscillation of a quiescent filament triggered by an extreme-ultraviolet (EUV) wave on 2022 October 2. Particularly, the filament oscillation involved winking phenomenon in Hα images and horizontal motions in EUV images. Originally, a filament and its overlying loops across AR 13110 and 13113 erupted with a highly inclined direction, resulting in an X1.0 flare and a non-radial coronal mass ejection. The fast lateral expansion of loops excited an EUV wave and the corresponding Moreton wave propagating northward. Once the EUV wave front arrived at the quiescent filament, the filament began to oscillate coherently along the horizontal direction, and the “winking filament” appeared concurrently in Hα images. The horizontal oscillation involved an initial amplitude of ∼10.2 Mm and a velocity amplitude of ∼46.5 km s−1, lasting for ∼3 cycles with a period of ∼18.2 minutes and a damping time of ∼31.1 minutes. The maximum Doppler velocities of the oscillating filament are 18 km s−1 (redshift) and −24 km s−1 (blueshift), which were derived from the spectroscopic data provided by the Chinese Hα Solar Explorer/Hα Imaging Spectrograph. The three-dimensional velocity of the oscillation is determined to be ∼50 km s−1 at an angle of ∼50° to the local photosphere plane. Based on the wave–filament interaction, the minimum energy of the EUV wave is estimated to be 2.7 × 1020 J. Furthermore, this event provides evidence that Moreton waves should be excited by the highly inclined eruptions.

Broad and Bidirectional Narrow Quasiperiodic Fast-propagating Wave Trains Associated with a Filament-driven Halo Coronal Mass Ejection on 2023 April 21

“…Notably, these computed magnetic field strength values should have significant uncertainties, which should be smaller than the actual value because the speeds utilized here are smaller than the actual speeds since the projection effect. Similar to the reports by Shen et al (2014aShen et al ( , 2014b, Dai et al (2023) reported a Moreton wave confirmed by CHASE, where the accompanying EUV wave triggered a simultaneous horizontal and vertical oscillation of a quiescent filament. Unfortunately, we carefully checked the data from CHASE and other devices and found that the Moreton wave did not accompany the present event.…”

Transverse Oscillation of Prominence and Filament Induced by an Extreme-ultraviolet Wave from the Far Side of the Sun

“…where B r , ρ p , and r 0 represent the radial component of the magnetic field, density, and scale height of the prominence, 1), respectively, and assuming ρ p = 4 × 10 −14 g cm −3 , we can estimate B r to be 5.4 G. Likewise, the radial magnetic field of the filament can also be calculated, yielding an estimate of 4.1 G. This is close to the values reported in previous papers (Hyder 1966;Shen et al 2014aShen et al , 2017Zhang & Ji 2018;Dai et al 2023).…”

“…As shown in Figure 9, the prominence exhibits simultaneous horizontal and vertical oscillations, indicative of transverse oscillations. This implies that the normal vector of the wave is inclined downward toward the prominence (Takahashi et al 2015;Dai et al 2023;Zheng et al 2023), which appears to provide strong support for the discussion of the properties of the EUV wave above (see also Figure 9 in Shen et al 2014b).…”

Sun-as-a-star Study of an X-class Solar Flare with Spectroscopic Observations of CHASE

“…This could be caused by two reasons. (i) Due to the oscillation, a quiescent filament moved downward and thus showed a redshifted absorption around 20:25 UT (Dai et al 2023). This could influence the full-disk Sun-as-a-star profiles of the flare.…”