Early Universe Packed with Massive Stars, Study Finds.

The first stars in the universe may have been over 10,000 times the mass of the sun, according to a new study. The early universe lacked elements heavier than hydrogen and helium, which are necessary for the rapid release of heat that allows dense clumps to collapse and trigger nuclear fusion. The first stars had to form under much different and more difficult conditions, resulting in gigantic clumps of neutral gas igniting their fusion cores all at once, skipping the stage where they fragment into small pieces. These stars would have been incredibly bright and would have lived extremely short lives, less than a million years, before dying in supernova explosions.