A critical analysis of main-sequence fitting in open clusters to derive the helium-to-metal enrichment ratio $\hat{I}”Y/\hat{I}”Z$

G. Valle, N. Ricci, M. Dell'Omodarme +3

We aim to investigate the feasibility of accurately determining the helium-to-metal enrichment ratio $\hat{I}”Y/\hat{I}”Z$ for open clusters using Gaia DR3 photometry. To test the reliability…