James Webb Space Telescope uncovers 300 mysteriously luminous objects. Are they galaxies or something else?

A series of red bubble looking spheres over a dark, starry background with four white cutout squares in the front enlarging four of the bubbles to show glowing balls of red light in each of the bubbles. — Hundreds of unusually bright early galaxy candidates have been identified in deep-field images from NASA's James Webb Space Telescope. (Image credit: Bangzheng "Tom" Sun)

Hundreds of unexpectedly energetic objects have been discovered throughout the distant universe, possibly hinting that the cosmos was far more active during its infancy than astronomers once believed.

Using deep-field images from NASA's James Webb Space Telescope (JWST), researchers at the University of Missouri identified 300 unusually bright objects in the early universe. While they could be galaxies, astronomers aren't yet sure what they are for certain. Galaxies forming so soon after the Big Bang should be faint, limited by the pace at which they could form stars. Yet these candidates shine far brighter than current models of early galaxy formation predict.

"If even a few of these objects turn out to be what we think they are, our discovery could challenge current ideas about how galaxies formed in the early universe — the period when the first stars and galaxies began to take shape," Haojing Yan, co-author of the study, said in a statement from the university.

To discover these objects, the team applied a method called the "dropout" technique, which detects objects that appear in redder wavelengths but vanish in bluer, shorter-wavelength images. This indicates the objects are extremely distant, showing the universe as it was more than 13 billion years ago.

To estimate distances, the team analyzed the objects' brightnesses across multiple wavelengths to infer redshift, age and mass. JWST's powerful Near-Infrared Camera and Mid-Infrared Instrument are designed to detect light from the farthest reaches of space, making them ideal for studying the early universe.