Eruption of a high-latitude prominence observed by the Siberian Radioheliograph and space-borne telescopes: I. Torus and helical kink instabilities in CME development

The eruption of a large prominence and the resulting development of a coronal mass ejection (CME) were observed on June 12, 2023 by the Siberian Radioheliograph in microwaves up to heliocentric distances exceeding two solar radii, space-borne telescopes in the extreme ultraviolet, and coronagraphs in white light. The evolution of the CME structural components was traced and their kinematic characteristics were measured. The CME components underwent two successive acceleration pulses, comparable in magnitude and duration. According to the observations, the first acceleration pulse was caused by torus instability of the magnetic flux rope associated with the prominence. At this stage, its expansion was self-similar and consistent with the expansion of the CME frontal structure. The frontal structure was an expanding arcade that encompassed the pre-eruption prominence. The second acceleration pulse was associated with helical kink instability, which manifested itself in the deformation of the top of the erupting prominence, visible as a helical protrusion. The development of helical kink instability affected the motion of the CME frontal structure, but did not influence the motion of the main body of the CME core, shown up as the massive part of the erupting prominence beneath the helical protrusion. After the completion of the helical kink instability, the coordinated self-similar expansion of all CME components recovered. The fact that the helical kink instability occurred much later than the torus instability excludes its involvement in causing the latter, as has sometimes been assumed.