Journal Article

Molybdenum Abundances in MINCE Stars

Lucertini, Francesca, Lombardo, Linda

2026

Overview

Molybdenum (Mo, Z = 42) is a neutron-capture element with seven stable isotopes that can be produced by different processes. Previous studies have shown a large scatter in molybdenum abundances for metal-poor ([Fe/H] < −1) stars, indicating that multiple nucleosynthetic channels are responsible for molybdenum production even at very low metallicity. To understand which different nucleosynthesis processes are involved in the chemical enrichment of this element in the Galaxy, a large sample of precise molybdenum abundance is required. In this study, we present molybdenum abundances of 27 metal-poor stars from the Measuring at Intermediate Metallicity Neutron-Capture Elements project sample. We derived molybdenum abundances using three Mo i lines at 550.6 nm, 557.0 nm, and 603.0 nm, which proved to be reliable for measuring Mo abundances in giant stars with [Fe/H] >−2. Our derived [Mo/Fe] abundance ratios show on average slightly higher values (∼0.2 dex) compared to the literature samples. This may be due to an observational bias or to non-local thermodynamic equilibrium effects. We also found that Gaia-Sausage-Enceladus candidate stars have lower [Mo/Fe] than the sample average, while the only Sequoia candidate star has a higher [Mo/Fe] than most sample stars.