Astronomers are astonished: an ancient dead galaxy has unexpectedly come to life (photo).

The James Webb Space Telescope has captured a new image of the irregular dwarf galaxy Leo P, located 5.3 million light-years away from us. More specifically, the photograph shows a section of the galaxy filled with a vast number of young blue stars. Despite the fact that star formation in this galaxy ceased over 12 billion years ago, it appears to have come back to life, as reported by Live Science.

All large galaxies, such as the Milky Way, originated from small primordial galaxies that grew by colliding with one another, with each interaction leading to the formation of more stars.

However, some primordial galaxies still exist in the universe in their original form for over 12 billion years, but they contain very few heavy chemical elements and are primarily composed of hydrogen and helium.

One such galaxy is the irregular dwarf galaxy known as Leo P. It is an isolated galaxy located far enough from the galaxies of the Local Group, which includes the Milky Way and the Andromeda galaxy, that large neighbors could not exert any influence on it.

Although astronomers first discovered the galaxy Leo P in 2013, it was only recently, with the help of the James Webb Space Telescope, that it was revealed that new stars are unexpectedly forming within it. Astronomers were quite surprised by this finding, as it was believed that isolated dwarf galaxies had ceased star formation around 12.8 to 13 billion years ago during a period known as the reionization epoch. This period in the history of the universe followed the so-called cosmic dark ages, when dense clouds of neutral hydrogen blocked light.

When the first stars appeared and subsequently exploded as supernovae, the cosmos was filled with powerful ultraviolet light capable of ionizing hydrogen atoms or breaking them back down into electrons and protons.

Astronomers studied thousands of stars in the dwarf galaxy Leo P and found that star formation occurred during the early stages of the universe's history, but then it ceased shortly after the reionization epoch. This was expected. However, astronomers also discovered that the dormant galaxy revived after several billion years, and new stars began to form again.

The astronomers collected data on three other isolated galaxies but found that star formation had ceased in all of them and had not resumed, so it remains unclear what exactly happened with Leo P.

The image from the Webb telescope shows a part of the Leo P galaxy in the lower right corner, filled with young blue stars. These stars have this color due to the presence of very few heavy chemical elements.