Investigating the evolution of erupting prominences seamlessly using mosaics of EUI/FSI and Metis

Understanding how erupting prominences evolve while propagating into the middle corona is essential for constraining the early phase of coronal mass ejections (CMEs).
This study aims to investigate the evolution of erupting prominences across the transition from the inner to the middle corona by Solar Orbiter EUI/FSI EUV observations with Metis coronagraph images. The unique characteristics of these instruments—notably the large field of view of the FSI imager, the overlap between their FOVs together with the high-cadence sequences acquired during Remote Sensing Windows—enable the construction of continuous mosaics. These mosaics trace prominence dynamics and morphology seamlessly from their onset in the low corona up to several solar radii. As part of this project, we are developing EUIMET, a dedicated tool that generates EUI/ FSI - Metis mosaics from calibrated data and provides configurable enhancement techniques and opacity level options to optimize the visibility of faint key coronal features.

We apply this method to the spectacular polar crown eruption of 20 October 2023, jointly observed by both instruments, and perform an in-depth morphological and kinematic characterization using triangulation and time–distance analyses. This case study serves as a proof of concept for future systematic investigations of eruptive prominences observed simultaneously in EUV, UV, and with-light regimes.

By providing a unified view of prominence evolution across the middle corona, this work aims to improve our understanding of CME initiation and propagation processes. The developed mosaic tool and data products will be made publicly available to support the solar physics community.