The James Webb Space Telescope (JWST) has created quite a stir since it went live last summer and has revealed many contenders for the title of “the oldest galaxy we’ve ever seen.” Still no clear decision on the winner this competitionbut last month JWST helped astronomers crown another champion. Confirm existence of faintest galaxy ever seen in early universe, results published in the journal Nature.

“Before the Webb telescope appeared just a year ago, we could not have dreamed of confirming the existence of such a faint galaxy,” said the astronomer at the University of California, Los Angeles. Tommaso Treuco-author of the new study.

Known as JD1, this galaxy is part of the first generation of galaxies to appear in history. our universe It is 13.8 billion years long. It’s about 13.3 billion light-years away, so we see it as it appeared when the universe was only a few hundred million years old, only 4% of its current age. This early period of the universe is known as “.reionization period”, when the first stars formed and lifted the universe out of darkness.

Astronomers are still trying to understand what exactly the first galaxies looked like and how they were able to illuminate the universe to create what we see today. Most of the newborn galaxies observed by JWST are bright, but they are considered extraordinary. Instead, astronomers suspect that fainter, smaller galaxies like JD1 do most of the heavy lifting during reionization.

“On the other hand, extremely faint galaxies like JD1 are much more abundant, so we think they are more typical of reionized galaxies,” said lead author Guido Roberts-Borsani. astronomer From UCLA, in the same newsletter.

JWST’s powerful infrared instruments were only part of the reason why astronomers were able to observe JD1. They also used a technique called gravitational lensing, in which light from a distant object is bent by the gravity of something huge in the foreground, such as a galaxy cluster. This acts like a magnifying glass, making distant objects larger and brighter – and visible in the case of the JD1.

“The combination of JWST and the magnification power of gravitational lenses is revolutionary,” Treu said. “We are rewriting the book on how galaxies formed and evolved right after. Big Bang“.