GLASS-z13 is only 300 million years old, and scientists believe that James Webb could find even older star clusters

The James Webb Space Telescope has found the oldest known galaxy in the universe.

The collection of stars – called GLASS-z13 – dates to just 300 million years after the big bang. This bests the previous oldest galaxy, known as GN-Z11, spotted by the Hubble Space Telescope by 100 million years.
Both of the galaxies have a mass equivalent to one billion suns, which the team suggests is what they would expect from 500 million-year-old – which could indicate that the stars formed even earlier than scientists think.

They are also relatively small compared to our own Milky Way, which is 100,000 light-years in diameter; GLASS-z13 is approximately 1600 light years across while GLASS-z11 is 2300 light years wide.

“We found two very compelling candidates for extremely distant galaxies,” says Rohan Naidu, a graduate student in the university’s astronomy department, told New Scientist.

“If these galaxies are at the distance we think they are, the universe is only a few hundred million years old at that point.”

It is possible that the James Webb Space Telescope will be able to see further back and discover galaxies only 200 million years old and could – as the researchers say in their findings, published online – be a “crucial step in fulfilling JWST’s mission of charting cosmic dawn.”

As well as this new galaxy, the James Webb Space Telescope has made numerous other observations since launching at Christmas, including photos of the Carina and Southern Wheel nebulae, a collection of galaxies known as Stephen’s Quartet and a spectrum of light from the exoplanet WASP-96b.