Astronomers have found the most distant example ever recorded of a compact, star-forming structure at the heart of a galaxy. The structure dates back more than 9 billion years, and its discovery is forcing scientists to reconsider how quickly galaxies developed complex internal organization.
The research, led by a team at Durham University and published in Monthly Notices of the Royal Astronomical Society, used data from the James Webb Space Telescope. According to Phys.org, the galaxy being studied is seen as it was just 4.5 billion years after the Big Bang.
At its center, researchers identified what is called a nuclear disk, a dense, rotating disk of stars that forms at the very heart of a galaxy. Nuclear disks are common in nearby, mature galaxies. Until now, they had never been observed this far back in cosmic history.
The discovery also points to a specific cause. The nuclear disk appears to have been built by a long, bar-shaped structure of stars stretching across the galaxy. These stellar bars appear in many present-day spiral galaxies and act by driving gas and stars toward the center, helping new structures form. Previous studies had shown that bars can form early in the universe's history, but there was no direct proof that they were already reshaping galaxies at this stage. This research provides that evidence.
Zoe Le Conte, the study's lead author from Durham University, said the finding was not expected. "This is a remarkable and unexpected discovery that will make astronomers revisit the idea of galaxy evolution and the influence of stellar bars in the early universe."
Le Conte also pointed to the broader pattern emerging from the telescope's data. "The extraordinary images and novel results from the James Webb Space Telescope continue to reveal that mature galaxies exist much earlier than we previously thought."
Despite its enormous distance, the newly discovered nuclear disk shares many of the same properties as nuclear disks found in galaxies today. It is compact, rich in young stars, and shows clear signs of organized growth. That similarity suggests galaxies did not slowly drift into their present-day forms over billions of years but instead matured rapidly and followed similar developmental pathways.
The findings also carry implications beyond galaxy structure. Nuclear disks are thought to act as reservoirs of gas that can feed the supermassive black holes believed to sit at the centers of most large galaxies, meaning this discovery may also offer new clues about how those black holes grew.
