image: An unsharp mask overlaid onto the F200W, F277W, and F356W filter composition. The white lines are logarithmic spirals fitted to points along the arm structures and a line segmen fitted to the approximately North to South aligned bar structure.
Credit: Courtesy image: Daniel Ivanov, et. al.
This news release is embargoed until 8-Jan-2026 at 12:00 PM EST
Research led by Daniel Ivanov, a physics and astronomy graduate student in the Kenneth P. Dietrich School of Arts and Sciences at Pitt, uncovered a contender for one of the earliest observed spiral galaxies containing a stellar bar, a sometimes-striking visual feature that can play an important role in the evolution of a galaxy. Our galaxy, the Milky Way, also has a stellar bar.
This finding helps constrain the timeframe in which bars could have first emerged in the universe. Analysis of light from the galaxy, called COSMOS-74706, places it on the cosmic timeline at about 11.5 billion years ago.
Daniel Ivanov can be reached at DAI34@pitt.edu.
“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 are scheduled to be presented at the 247th meeting of the American Astronomical Society on Thursday, Jan. 8, 2026.
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 isn’t an object itself, but a dense collection of stars and gas that is aligned in such a way that in images taken perpendicular to a galactic plane, there appears to be a bright line bisecting the galaxy.
Stellar bars can play a role shaping their galaxy’s evolution by funneling gas inward from the outer reaches of a galaxy, feeding the supermassive black hole in the center and dampening star formation throughout the stellar disk.
Other researchers have reported earlier barred spiral galaxies, but the analyses of those are less conclusive because the methods used to analyze the lights’ redshifts are not as definitive as spectroscopy, which was used to validate COSMOS-74706. In other cases, the galaxy’s light was distorted as it passed by a massive object, a phenomenon known as gravitational lensing.
In essence, Ivanov said, “It's the highest redshift, spectroscopically confirmed, unlensed barred spiral galaxy.”
He wasn’t necessarily surprised to find a barred spiral galaxy so early in the universe’s evolution. In fact, some simulations suggest bars forming at redshift 5, or about 12.5 billion years ago. But, Ivanov said, “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 work is based in part on observations made with the NASA/ESA/CSA James Webb Space Telescope with data from Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127, which is supported by NASA. Work was also supported by the Brinson Foundation.
Method of Research
Data/statistical analysis
Subject of Research
Not applicable