
The first generation of stars, formed from primordial hydrogen and helium, predicted to be massive.Population III stars are the hypothetical first generation of stars, formed from the primordial gas of hydrogen and helium left over from the Big Bang. Because this gas contained no heavier elements (which act as coolants), these stars are predicted to have been extremely massive — often hundreds of times the Sun's mass — and to have burned hot and fast, ending in spectacular supernovae that seeded the universe with the first heavy elements.
The concept was proposed in the 1960s by astrophysicists like Yakov Zel'dovich and others, who realized that the first stars must have differed from modern ones. Direct observation remained elusive until the James Webb Space Telescope began searching for them in the early 2020s.
Without metals, the primordial gas could not radiate heat efficiently, so it stayed hot and resisted fragmentation into small clumps. This allowed large clouds to collapse into single, enormous stars. Their intense ultraviolet radiation and short lifetimes (a few million years) meant they exploded quickly, dispersing elements like carbon, oxygen, and iron into space, which then enabled the formation of later, smaller stars like our Sun.
They are a key target for the James Webb Space Telescope, which aims to observe them to understand the early universe's chemical evolution and the seeds of supermassive black holes.
Population III stars may have been so massive that some collapsed directly into black holes without a supernova, potentially explaining the origin of the supermassive black holes at the centers of galaxies.






















