The James Webb Space Telescope has potentially identified the most distant known galaxy, a bright star system existing just 290 million years post-Big Bang, NASA announced Thursday. Since its launch in 2022, Webb has revolutionized our understanding of the universe, offering unprecedented glimpses into its early stages.
Researchers emphasize the profound implications of this discovery for understanding the Cosmic Dawn. The galaxy, named JADES-GS-z14-0, was first spotted in early 2023 by an international team of astronomers. Initially uncertain if it was truly a record-breaker, the team conducted further observations to confirm its status.
Surprising brightness and further observations
“The source was surprisingly bright, which we wouldn’t expect for such a distant galaxy,” noted researchers Stefano Carniani from Scuola Normale Superiore in Italy and Kevin Hainline from the University of Arizona. Additional observations in October and January using Webb’s NIRCam and NIRSpec confirmed the galaxy’s properties.
This discovery surpasses the previous record-holder, JADES-GS-z13-0, which existed 320 million years after the Big Bang. The findings raise new questions about galaxy formation in the early universe. The galaxy, 1,600 light-years across, appears to consist mainly of young stars, indicating significant mass and luminosity.
Unexpected presence of oxygen
Further analysis revealed the presence of oxygen, suggesting that multiple generations of massive stars had already lived and died by the time we observed this galaxy. These observations challenge existing predictions about the appearance and composition of the earliest galaxies, reshaping our understanding of the universe’s infancy.
Taken together, the observations of JADES-GS-z14-0 upend astronomical predictions of what the earliest galaxies may have looked like following the Big Bang 13.8 billion years ago.
Given the relatively small portion of the night sky they looked at, it’s highly likely more luminous galaxies at possibly even earlier times will be found in the coming years, said the researchers, who will now look to publish their findings in a peer-reviewed journal.