Low-Metallicity Blue Compact Dwarfs as Templates for Primordial Star Formation

Understanding how galaxies formed their first stars is a vital cosmological question, but the study of high-redshift objects, caught in the act of forming their first stars, is difficult. Here we argue that two extremely low-metallicity Blue Compact Dwarf galaxies (BCDs), IZw18 and SBS0335-052, could be local templates for primordial star formation, since both lack evolved ($>$1 Gyr) stellar populations; but they form stars differently.