Initiation mechanisms of the erupting prominences

Solar prominences are common features of the solar atmosphere and are often considered as precursor of large-scale dynamic events such as flares and coronal mass ejections (CMEs) which can disrupt the interplanetary medium and trigger geomagnetic storms on Earth. The main aim of this thesis is to provide a comprehensive understanding of these remarkable structures strongly connected with the magnetic field of the Sun. Prominence eruptions undergo three distinct phases: a slow rise, an acceleration and a propagation phase. The study of the first two can provide important information about the forces that impact on them. Six solar prominence eruptions with different morphologies were selected to unravel their initial triggering mechanisms. The study utilizes high cadence observations obtained from the He II 304 A passband of the Full Sun Imager (FSI) telescope aboard the Solar Orbiter during the period between 2021 and 2022. Building on the previous work of M. Mierla et al. (2013), the outer edge of the prominence structures were fitted with power-law polynomial functions to extract the best-fitting models characterizing their behaviour and to determine the initial time at which the prominences began to accelerate. In addition, exponential and parabolic profiles were investigated as alternative scenarios. The obtained results were highly dependent on the chosen initial time and the specific event under investigation. Some events exhibited an exponential growth pattern, indicative of helical kink or torus instability, while others were consistent with a power-law model with a slope (m) of 3 or lower, which aligns with a torus instability arising from a sufficiently large initial perturbation. In certain cases, no acceleration was observed, suggesting the involvement of multiple triggering mechanisms rather than a single unified model to fully describe these features.