Astronomers noticed a galaxy which suddenly stopped forming new stars more than 13 billion years ago.

Using the James Webb Space Telescope, the team of astronomers led by the University of Cambridge detected a galaxy that had already died when the universe was only 700 million years old. It is the oldest such galaxy ever observed.

This galaxy appears to have lived fast and died young: Star formation happened quickly and stopped almost as quickly, which is unexpected for such an early stage of the universe’s evolution. In particular, the galaxy experienced a short and intense phase of star formation in a period between 30 and 90 million years. But between 10 and 20 million years before the time point observed with Webb, star formation suddenly stopped.

However, it is not clear whether this state of the galaxy is temporary or permanent and what caused it to stop forming new stars. Astronomers say that although it appears dead at the time of sighting, it is possible that in the 13 billion years since then, this galaxy may have come back to life and started forming new stars again.

The results of the research, published in the journal Nature, could help astronomers understand how and why galaxies stop forming new stars, and whether the factors that influence star formation have changed over billions of years.