The First Stars Remain Hints in a Blueberry Galaxy

A team searched 84 strong helium-emitting galaxies at redshifts three to seven for signs of the first metal-free stars, combining ultraviolet line ratios, metallicity estimates, active-galaxy screening and resolved stellar-population fits. It found no pristine Population III galaxy. One object nicknamed The Blueberry is its strongest candidate for a mixed Population III and enriched-star system, but an enriched starburst could also explain its young, blue stellar population. The study argues that spatially localized early-star signatures can disappear in whole-galaxy measurements.