(ORDO NEWS) — A team of astronomers from the Max Planck Institute for Astronomy has identified the “poor old heart of the Milky Way” – a population of stars that have been preserved in the core of the Galaxy since its formation.
Our home galaxy, the Milky Way , has been forming over the past 13 billion years almost as long as the universe has existed.
Over the past decades, astronomers have been able to reconstruct many stages of galactic history, while their method is not too different from the dating methods used by archaeologists.
So, for example, by excavating an ancient city, scientists can determine which buildings were built earlier and which later.
This is indicated both by the location of the buildings (it is logical that the oldest part of Moscow is located around the Kremlin), and the materials or methods of construction used to create them.
“Space archaeologists” do the same in this regard, determining the age of stars by their chemical composition and location in the universe.
To reconstruct the history of the Milky Way from the very beginning, researchers at the Max Planck Institute for Astronomy (Germany) determined the age of thousands of the oldest observable stars that are at the subgiant stage.
This allowed them to “look back” 11 billion years, to the time of the merger of the Milky Way with a dwarf galaxy, whose remnants were discovered in 2018.
Since the oldest stars contained quite a lot of heavy elements, astronomers suggested that they were not at all the first in history and that several generations of early stars had already existed before them, after the explosion saturating the interstellar space with metal atoms.
This is consistent with the assumption that before the formation of the Milky Way, there were three or four protogalaxies that formed close to each other and eventually merged together.
It was they who became the “heart” of the Milky Way, preserved in the center of our Galaxy, and in the end, scientists managed to find it.
It turned out, as the researchers expected, the “poor old heart of the Milky Way” is located at a distance of approximately 30 thousand light years from the center of the Galaxy and represents a group of stars poor in metals, whose age exceeds 12.5 billion years.
Perhaps, with additional data, scientists will even be able to determine which of the protogalaxies each star belongs to, which will make it possible to clarify the origin of the entire Milky Way.
—
Online:
Contact us: [email protected]
Our Standards, Terms of Use: Standard Terms And Conditions.