The dataset provides experimental data on the entry of Abrikosov vortices in superconducting nanostring resonators, investigated through displacement-noise spectroscopy within the framework of cavity optomechanics. This version v1 dataset, published on May 21, 2026, contains a single ZIP file (96.5 kB) with software written in Python. The research was supported by the European Commission, the Munich Center for Quantum Science and Technology, and the Deutsche Forschungsgemeinschaft. The purpose is to support the related preprint on arXiv and facilitate further study of mechanical motion in superconducting systems at quantum scales.