When Did The First Stars Appear In The Universe?
“But there’s more science to be done. Even with James Webb, we likely won’t get all the way to the very first star of all, but we’re very likely to gain a much better handle on exactly where they are and when they are. And as for the first pristine stars? The first stars verified to have nothing other than hydrogen and helium in them? If nature is kind to us, James Webb won’t only bring us the very first one of those, but will bring us many examples.
The Universe is out there, waiting for us to discover it. If we want to know the answer, all we need to do is look. As we build better observatories and take better data, our understanding of all that’s out there will only improve.”
If we look out as far as we can, there’s a big gap between what we know and what must be there. The most distant galaxy we’ve ever found is GN-z11, whose light comes from when the Universe was only 400 million years old. The next picture we have is the cosmic microwave background, emitted from when the Universe was a mere 380,000 years old. At that point, there were no stars; by time we get to 400 million years of age, we have quite large and bright galaxies. So when did the first stars actually, truly appear? It’s a question that we know an awful lot about what the answer must look like, but we’re still a few steps away from actually finding them.