SNe II the rescue: An H0 determination based on a dedicated data set of SNe II in the Hubble flow

Building on the proof-of-principle demonstration presented by C. Vogl, this talk introduces the adH0cc project (Accurate Determination of H0 with Core-Collapse supernovae), which aims to refine the determination of the Hubble constant (H0) using Type II supernovae (SNe II). adH0cc applies the tailored expanding photosphere method to a dedicated, high-quality dataset of more than 20 SNe II in the Hubble flow, obtained through an ESO-VLT Large Programme specifically designed to minimise observational uncertainties. The adH0cc dataset addresses the limitations of existing literature data, including improvements in data quality, temporal coverage, and sample size. These enhancements enable a significant reduction in statistical and systematic uncertainties compared to the proof-of-principle analysis. Additional strategies employed by adH0cc to further refine the H0 measurement include a rigorous control of systematic effects, such as host-galaxy extinction and peculiar-velocity corrections. Together, the adH0cc project allows for a critical test of the Hubble tension and highlights the growing role of SNe II in modern cosmology.