NASA’s James Webb Telescope (JWST) has discovered a 13.5-billion-year-old galaxy, which is now the oldest in the universe visible to human eyes. The galaxy, called GLASS-z13 (GN-z13), formed just 300 million years after the Big Bang that occurred before 13.8 billion years old.
According to the British newspaper “Daily Mail”, the oldest galaxy before this galaxy was GN-z11, which dates back to 400 million years after the birth of the universe.
JWST captured a look at GN-z13 using the Near Infrared Camera (NIRCam) instrument, which is capable of detecting light from the oldest stars and galaxies.
This telescope uses a wide range of infrared light to see past time, and this is done by analyzing the time it takes for the light to travel through space.
While investigating region GN-z13, JWST also observed GN-z11, scientists from the Harvard and Smithsonian Center for Astrophysics in Massachusetts note that although both are ancient, each galaxy is very young.
GN-z13 is about 1,600 light-years across and GLASS z-11 spans 2,300 light-years, which is very small compared to our Milky Way, which is about 100,000 light-years across.
The paper published in arXiv notes that both galaxies have the mass of a billion suns, because they formed so soon after the Big Bang.
The team suggests that this happened when galaxies were growing and devouring stars in the region, and the researchers shared in the paper: “These two objects are already setting new constraints on the evolution of galaxies in the era of cosmic dawn.”