Astronomers using the James Webb Space Telescope identified a galaxy called Hebe from 400 million years after the big bang that shows spectral signatures matching what the first stars—made almost entirely of hydrogen and helium—should look like. The detection of ionized helium and hydrogen lines strongly suggests these are Population III stars, the universe's first massive stars that scientists have never conclusively observed before. However, the article acknowledges the evidence isn't ironclad yet—current precision can't completely rule out heavier elements, and the galaxy contains far more of these stars than existing simulations predict should exist together.