What Was It Like When The Universe Made Its Second Generation Of Stars?
“The very first stars live only an extremely short time, owing to their high masses and large luminosities and rates-of-fusion. When they die, the space around them becomes polluted with the fruits of their lives: heavy elements. These heavy elements enable the second generation of stars to form, but they now form differently. The heavy elements radiate heat away, giving rise to a less massive, more diverse generation of stars, some of which survive even to the present day.
When the James Webb Space Telescope begins operations, it may yet reveal a population of these first stars, likely to be found alongside polluted, second-generation stars. But once these second-generation stars begin to form, they make something else possible: the first galaxies. And that, in just a few years, is likely where the James Webb Space Telescope will truly shine.”
The first stars in the Universe, as astronomers define them, are stars made out of pristine materials left over from the Big Bang: almost exclusively hydrogen and helium. Because of this, their options are limited. They’re all very massive, they have no rocky planets around them, they live a short time, and they almost all die in a supernova. That’s not a life-friendly environment! But all of that changes with the second generation of stars, which forms just a few million years after the first. Some of these may even survive in the Milky Way to the present day… and we might have even found them already.