An ‘alien’ called the Oosterhoff dichotomy? E. Luongo, V. Ripepi, M. Marconi, Z. Prudil, M. Rejkuba, G. Clementini and G. Longo A&A, 690 (2024) L17 Published online: 21 October 2024 DOI: 10.1051/0004-6361/202451596