The occurrence and impact of carbon-oxygen shell mergers in massive starsL. Roberti, M. Pignatari, H. E. Brinkman, S. K. Jeena, A. Sieverding, A. Falla, M. Limongi, A. Chieffi and M. LugaroA&A, 698 (2025) A216DOI: https://doi.org/10.1051/0004-6361/202554461