Astronomers Uncover Ancient Barred Spiral Galaxy COSMOS-74706

A team of astronomers has identified a potential contender for one of the earliest observed barred spiral galaxies, named COSMOS-74706. Observations obtained from the James Webb Space Telescope reveal the galaxy’s distinct spiral arms and a prospective central bar structure, which plays a significant role in galactic evolution. This groundbreaking discovery positions COSMOS-74706 at approximately 11.5 billion years ago, indicating it formed just two billion years after the birth of the universe.

The findings were presented during the 247th meeting of the American Astronomical Society on January 8, 2026. The research was supported by Yingjie Cheng, a postdoctoral researcher in astronomy at the University of Washington, who previously conducted this study as a doctoral student at the University of Massachusetts Amherst. Cheng emphasized the significance of the discovery, stating, “Stellar bars are typically seen in mature, well-evolved galaxies, so finding one just two billion years after the Big Bang is remarkable.”

The research team, which included graduate student Daniel Ivanov from the University of Pittsburgh, analyzed the galaxy’s physical properties and evolutionary history. They noted that the “bar” in a barred galaxy is not an individual object but rather a dense collection of stars and gas aligned to create the appearance of a bright line bisecting the galaxy in specific images.

Understanding Stellar Bars and Their Impact

Although stellar bars may seem like permanent features, they are actually fluctuating density waves resulting from various instabilities within a galaxy. These instabilities can arise from external gravitational forces, such as tidal perturbations caused by interactions with nearby galaxies. Ivanov explained, “If you have a close interaction with a nearby galaxy, that can actually trigger the global instability that leads to the formation of a stellar bar.”

Even in the absence of external influences, a stable galactic disc can gradually become unstable, potentially leading to the emergence of stellar bars over time. These structures are believed to form and dissipate multiple times throughout a galaxy’s lifetime. The presence of a stellar bar can significantly influence a galaxy’s evolution by funneling gas inward from its outer regions, contributing to the accretion of material into the supermassive black hole at the galaxy’s center.

The discovery of COSMOS-74706 was part of a broader effort to catalog barred and non-barred galaxies within a specific region of space. During this process, the research team identified several galaxies with exceptionally high redshifts, indicating that their light had been traveling for a considerable amount of time.

While previous reports of early barred spiral galaxies exist, the analyses conducted on those galaxies lacked the definitive measurement methods used to validate COSMOS-74706. Ivanov noted that while simulations predict bars could have formed as early as 12.5 billion years ago, the findings of COSMOS-74706 help to refine the timescales for bar formation in the universe. He remarked, “In principle, I think that this is not an epoch in which you expect to find many of these objects. It helps to constrain the timescales of bar formation. And it’s just really interesting.”

This research was funded by NASA and The Brinson Foundation. For further inquiries, interested parties can contact Cheng at [email protected].

This article is based on a press release from the University of Pittsburgh.