Millions of years after the Big Bang, a point of light was born in the dark universe. This first star began to emit radiation, which knocked electrons from the mist around hydrogen. More stars will form, transforming almost all opaque, neutral hydrogen atoms into clear soups of ionized hydrogen, allowing them to move freely through the light-expanding universe. This was the end of the dark ages of the universe and the beginning of the Galactic Layer.
These first stars and the galaxies they formed were very different from those found in modern universes. One was made almost entirely of hydrogen and helium and from trace amounts of lithium, as there were no heavy elements yet. “The chemistry we see is only made with stars.” Richard Ellis University College London.
Until 2022, the oldest known galaxy was known as GN-Z11, which formed about 400 million years after the Big Bang. This knows this because of a property called Redshift. The expansion of the universe becomes faster, the further the object is, the faster it moves, the more light it becomes. As light takes longer to travel, the more distant an object and its redshift increases, the earlier we see in the history of the universe. The redshift of the GN-Z11 is approximately 11.
However, thanks to James Webb Space Telescope (JWST), we discovered that there are galaxies that are much older than the GN-Z11. JWST is bigger and more sensitive…
Source: www.newscientist.com
