JPL-Caltech/NASA
This artist’s concept depicts a top-down view of the Milky Way, a striking barred spiral galaxy.
Subscribe to CNN’s Wonder Theory science newsletter. Immerse yourself in the universe with news on groundbreaking discoveries, scientific advancements and more.
CNN
—
Astronomers have observed a fascinating phenomenon in the far reaches of the universe — a galaxy that bears a striking resemblance to the Milky Way, challenging fundamental theories on galaxy evolution.
The remote system, identified as ceers-2112, was detected by an international team using the James Webb Space Telescope.
Similar to our own galaxy, the newly discovered ceers-2112 is a barred spiral galaxy, representing the most distant of its kind ever observed. The centrally located bar structure is composed of stars.
Ceers-2112 formed shortly after the big bang, estimated to have occurred 13.8 billion years ago, with the galaxy’s distinctive structure already in place just 2.1 billion years later.
With the significant distance between Earth and these early universe objects, telescopes like Webb allow scientists to effectively look into the past when observing light from the distant cosmos.
“Surprisingly, this discovery reveals that galaxies resembling our own existed 11,700 million years ago, when the Universe was only 15% of its current age,” said lead study author Luca Costantin in a statement. Costantin is a postdoctoral researcher at Spain’s Centro de Astrobiología in Madrid, affiliated with the Spanish National Research Council.
Astronomers were astonished to encounter such an ordered and structured galaxy during a time when other galaxies were much more irregular. While large spiral galaxies are prevalent in the Milky Way’s vicinity, this was not always the case.
This revelation, made possible by Webb’s highly sensitive light-detecting capabilities, is reshaping scientists’ comprehension of galaxy formation and the universe’s early stages.
“The discovery of ceers-2112 suggests that galaxies in the early universe could be as ordered as the Milky Way,” said study coauthor Alexander de la Vega, a postdoctoral researcher at the University of California, Riverside. “This is surprising because galaxies were much more chaotic in the early universe, and very few resembled the Milky Way.”
The findings of the study were published November 8 in the journal Nature.
Astronomers previously thought that barred spiral galaxies like the Milky Way did not emerge until the universe had reached at least half of its current age, due to the belief that it took several billion years of galactic evolution for the massive star collections within galaxies to form central bars.
The bars take shape as stars within spiral galaxies rotate in an orderly manner, as observed in the Milky Way. Until now, astronomers did not believe that early galaxies had enough stability for bars to form or endure.
However, the discovery of ceers-2112 suggests that this evolution only took about 1 billion years or less, according to de la Vega.
“Nearly all bars are found in spiral galaxies,” de la Vega said. “The bar in ceers-2112 suggests that galaxies matured and became ordered much faster than we previously thought, which means some aspects of our theories of galaxy formation and evolution need revision.”
De la Vega believes that astronomers will need to adjust their theoretical models for galaxy formation and evolution by incorporating the amount of dark matter present in the earliest galaxies.
Although dark matter has never been directly detected, it is believed to account for 85% of the total matter in the universe — something the European Space Agency’s Euclid telescope has been designed to map. Dark matter may have played a role in the formation of the bars.
The discovery also suggests that bars can be detected in early galaxies, despite the fact that the oldest galaxies are much smaller.
“The discovery of ceers-2112 paves the way for more bars to be discovered in the young universe,” de la Vega said. “Initially, I thought detecting and estimating properties of bars in galaxies like ceers-2112 would be fraught with measurement uncertainties. But the power of the James Webb Space Telescope and the expertise of our research team helped us place strong constraints on the size and shape of the bar.”
