Research led by Daniel Ivanov, a physics and astronomy graduate student in the Kenneth P. Dietrich School of Arts and Sciences at the University of Pittsburgh, has identified a contender for one of the earliest known spiral galaxies containing a stellar bar, a structure that plays a role in how galaxies evolve. The system, designated COSMOS-74706, appears as a barred spiral galaxy from a time wh Los Angeles CA (SPX) Jan 09, 2026
Research led by Daniel Ivanov, a physics and astronomy graduate student in the Kenneth P. Dietrich School of Arts and Sciences at the University of Pittsburgh, has identified a contender for one of the earliest known spiral galaxies containing a stellar bar, a structure that plays a role in how galaxies evolve. The system, designated COSMOS-74706, appears as a barred spiral galaxy from a time when the universe was about 2 billion years old, and the Milky Way is also classified as a barred spiral.
The team's analysis places COSMOS-74706 at roughly 11.5 billion years in the past on the cosmic timeline, showing that barred spirals were already in place by that epoch. This timing now serves as an observational marker for when stellar bars had formed and begun to affect galaxy evolution.
Daniel Ivanov can be reached at [email protected]. "This galaxy was developing bars 2 billion years after the birth of the universe," Ivanov said. "Two billion years after the big bang."
The findings were presented at the 247th meeting of the American Astronomical Society on Thursday, Jan. 8, 2026. The result adds an observational data point for models of how disk galaxies and their central structures assembled over cosmic time.
"The defining feature of these galaxies is right in the name: 'A stellar bar is a linear feature at the center of the galaxy,'" Ivanov said. The bar is not a separate object, but a dense collection of stars and gas that, in images taken perpendicular to the galactic plane, appears as a bright line bisecting the galaxy.
Stellar bars shape a galaxy's evolution by funneling gas inward from the outer reaches of the disk, feeding the supermassive black hole in the center and reducing star formation throughout the stellar disk by moving gas away from star-forming regions.
Other researchers have reported barred spiral galaxies at earlier cosmic epochs, but those studies rely on less definitive redshift measurements than spectroscopy or on systems whose light is distorted by gravitational lensing. For COSMOS-74706, spectroscopic measurements secure the galaxy's redshift, and the system is not lensed, which strengthens the case that it is an early barred spiral.
In Ivanov's words, "It's the highest redshift, spectroscopically confirmed, unlensed barred spiral galaxy." Some simulations indicate that bars can form as early as redshift 5, about 12.5 billion years ago, but such galaxies are expected to be rare at those times.
"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," Ivanov said. The confirmed observations of COSMOS-74706 now provide a concrete limit on how early barred structures are known to have existed in disk galaxies.
This work is based on observations made with the NASA/ESA/CSA James Webb Space Telescope, with data from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 and supported by NASA. The research also received support from the Brinson Foundation and relies on data and statistical analysis to characterize the galaxy and its barred structure.
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