The Metallicity Distribution of the Ultra-Faint Dwarf Galaxy Segue 1
This study updated Segue 1's metallicity distribution function (MDF) by measuring metallicities from 45 stars, six times more than previously reported. The resulting MDF shows a single peak at an average [Fe/H] of -2.52, suggesting a brief, continuous star formation episode rather than distinct star clusters. This supports Segue 1's classification as a galaxy and indicates it retained supernova ejecta.