Evolution of the Coronal Cavity From the Quiescent to Eruptive Phase Associated with Coronal Mass Ejection

Abstract

Abstract We present the evolution of a coronal cavity encompassing its quiescent and eruptive phases in the lower corona. Using multiple vantage-point observations from the SDO/AIA, STEREO SECCHI/EUVI, and PROBA2/Sun Watcher with the APS and Image Processing (SWAP) extreme ultraviolet (EUV) imagers, we capture a sequence of quasi-static equilibria of the quiescent cavity, which exhibited a slow rise and an expansion phase during its passage on the solar disk from 2010 May 30 to June 13. By comparing the decay-index profiles of the cavity system during the different stages of its quiescent and pre-eruptive phases, we find that the decay-index value at the cavity centroid height can be used as a good indicator to predict the cavity eruption in the context of torus instability. Combining the observations of SWAP and the Large Angle and Spectrometric Coronagraph Experiment C2/C3, we show the evolution of the EUV cavity into the white-light cavity as a three-part structure of the associated coronal mass ejection that was observed to erupt on 2010 June 13. By applying successive geometrical fits to the cavity morphology, we find that the cavity exhibited non-self-similar expansion in the lower corona, below 2.2 ± 0.2 R S, which points to the spatial scale for the radius of the source surface where the coronal magnetic field lines are believed to become radial. Furthermore, the kinematic study of the erupting cavity captures both the “impulsive” and “residual” phases of acceleration along with a strong deflection of the cavity at 1.3 R S. We also discuss the role of driving forces behind the dynamics of the morphological and kinematic evolution of the cavity.