Findings in title quoted from linked summary released by the University of Missouri.

Excerpt:

>In a new study, a team of astronomers led by Haojing Yan at the University of Missouri used data from NASA’s James Webb Space Telescope (JWST) Early Release Observations and discovered 87 galaxies that could be the earliest known galaxies in the universe.

>The finding moves the astronomers one step closer to finding out when galaxies first appeared in the universe — about 200-400 million years after the Big Bang, said Yan, associate professor of physics and astronomy at MU and lead author on the study.

>“Finding such a large number of galaxies in the early parts of the universe suggests that we might need to revise our previous understanding of galaxy formation,” Yan said. “Our finding gives us the first indication that a lot of galaxies could have been formed in the universe much earlier than previously thought.”

>In the study, the astronomers searched for potential galaxies at “very high redshifts.” Yan said the concept of redshifts in astronomy allows astronomers to measure how far away distant objects are in the universe — like galaxies — by looking at how the colors change in the waves of light that they emit.

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>The JWST was critical to this discovery because objects in space like galaxies that are located at high redshifts — 11 and above — can only be detected by infrared light, according to Yan. This is beyond what NASA’s Hubble Space Telescope can detect because the Hubble telescope only sees from ultraviolet to near-infrared light.

>“JWST, the most powerful infrared telescope, has the sensitivity and resolution for the job,” Yan said. “Up until these first JWST data sets were released [in mid-July 2022], most astronomers believed that the universe should have very few galaxies beyond redshift 11.

>“At the very least, our results challenge this view. I believe this discovery is just the tip of the iceberg because the data we used only focused on a very small area of the universe.

>“After this, I anticipate that other teams of astronomers will find similar results elsewhere in the vast reaches of space as JWST continues to provide us with a new view of the deepest parts of our universe.”

Haojing Yan et al. First Batch of z ≈ 11–20 Candidate Objects Revealed by the James Webb Space Telescope Early Release Observations on SMACS 0723-73. The Astrophysical Journal Letters 942 L9 (2023). https://doi.org/10.3847/2041-8213/aca80c