The Milky Way has swallowed 'the child of the Big Bang'

A series of objects 12-13 billion years old have just been found in the halo of the Milky Way, the galaxy containing the Earth.

According to Professor Anna Frebel from the Massachusetts Institute of Technology (MIT - USA), the objects recently found in the Milky Way are extremely ancient stars, born at a time when the first galaxies were forming in the universe. .

They date back 12-13 billion years , a very short time after the Big Bang - the event that created the universe, according to a research summary on Sci-News.

The Milky Way from an angle taken from the Very Large Telescope (VLT) System of the European Southern Observatory (ESO) - (Photo: ESO).

These ancient stars were certainly not born within the bright Milky Way we still see in the sky, but belonged to much more ancient dwarf galaxies.

These primordial galaxies may have been located too close to the location where the Milky Way later formed.

The galaxy containing Earth belongs to the group of "monster" galaxies in the universe, growing strongly. Therefore, this "junior" quickly swallowed the surrounding small primitive galaxies, absorbing ancient stars into the galactic halo.

Although we often call it the Milky Way, the Milky Way is actually a spiral galaxy with a circular main disk in the middle . Earth resides at this stellar edge.

And the primordial stars wander in the galaxy's halo, a fainter spherical structure that covers the main disk.

The discovery of these ancient stars is a treasure for astronomers.

Because research on "children of the Big Bang" - which is how scientists call the first objects born when the universe formed - is extremely difficult.

Despite cutting-edge instruments like the James Webb Space Telescope, which can traverse billions of years of space and time to capture ancient images, all they found were galaxies. super dim dwarf.

Therefore, capturing the "fossils" of the early universe right inside the Milky Way is a great opportunity to more clearly study the nature of these objects.

The ancient origin of the stars has also been determined through preliminary analysis, showing that they have similar compositions to ancient ultrafaint dwarf galaxies that previous studies have identified.

In addition, the tracking of three of them - located 30,000 light years from Earth - has completely different motions than the stars in the main disk.

This movement shows that they once belonged to another parent galaxy, absorbed by the Milky Way during its growth.

Absorbing other galaxies is common for large galaxies such as the Milky Way. It is estimated that the galaxy in which Earth resides has swallowed more than 20 galaxies since its formation, including quite large galaxies, to achieve today's size and complex structure.

The method of searching for ancient stars that the MIT team has just applied promises to help identify a series of other stars and primitive objects lurking among the more than 400 billion stars of the Milky Way, also opening the door. at the dawn of the universe.

The research has just been published in the scientific journal Monthly Notices of the Royal Astronomical Society.