Coronal wave associated with a non-radial filament eruption observed by the Solar Dynamics Observatory

Abstract

We analyse a coronal wave that occurred during a non-radial filament eruption observed by the Solar Dynamics Observatory on 2011 August 10. The filament underwent an extended time activation phase followed by an abrupt ejection, and during its evolution it rotated towards the south. The eruption was accompanied by fast-wave and slow-perturbation phenomena. The slow perturbation occurred before the eruption and impulsively accelerated almost simultaneously with the eruption; its final propagation velocity was about 300 km s-1, approximately equal tothat of the associated coronal mass ejection. The slow perturbation is possibly an indicator of an expanding loop overlying the filament. The fast wave was probably caused by the rapid inflation of the overlying loop. Because of the eruption location close to the limb and the effect of the complex environment, the fast coronal wave showed different characteristics in different directions: The kick-off speed was about 430-480 km s-1, showing deceleration in some directions, and a high speed of up to 782 ± 21 km s-1 in another direction. All the results indicate that the coronal wave was a fast-mode magnetohydrodynamic wave, and the wavelet analysis confirms the periodic wave nature of the coronal wave.