Gaia Telescope Unveils the Origins of the Milky Way Galaxy Formed Over 12 Billion Years Ago
The Gaia space telescope, tasked with mapping the Milky Way, has identified two groups of primordial stars at the heart of our galaxy, marking the origins of its formation more than 12 billion years ago, according to a recent study.
These "stellar streams," each with a mass equivalent to 10 million Suns and their rhythmic rotational movement, are likened to the "first building blocks" of the ancient core of the Milky Way. This is where the earliest stars were born before the galaxy grew and assumed its current spiral shape, said Khyati Malhan of the Max Planck Institute for Astrophysics in Germany to Agence France-Presse.
The lead author of the study, published in the Astrophysical Journal, explained, "This is the first time we have been able to identify parts of this primordial galaxy," which were named "Shakti and Shiva," after two Hindu deities whose union is said to have resulted in the creation of the universe.
The European Space Agency's Gaia probe, operational 1.5 million kilometers from Earth for a decade, delivered a three-dimensional map in 2022 detailing the positions and movements of over 1.8 billion stars.
This map revealed a cluster of stars dubbed "the old poor hearts" due to their great age, indicated by their low metallicity (a chemical index of a star's age) and their central location.
This discovery was a significant step for galactic archaeology, aiming to reconstruct the various epochs in the history of the Milky Way "in the same way archaeologists reconstruct the history of an ancient city," stated the Max Planck Institute in a release.
Thus, the model of the Milky Way's evolution resembles an "ancient central city surrounded by newer regions," according to the institute. However, "The further back we go in time and space, the blurrier the picture of the galaxy's history becomes," Malhan remarked.
Astronomers in 2022 explored this ancient core, analyzing a sample of 6 million stars for their chemistry and positions, notably using artificial intelligence.
This led them to identify two "stellar streams" (Shakti and Shiva), formed between 12 and 13 billion years ago in the early epochs of the Milky Way.
Surprisingly, the stars within these streams possess unusually high metal contents for their age, potentially indicating they originated from a previous generation of stars. As these predecessors died, they released chemical elements that "seeded" the interstellar gas from which the Shakti and Shiva stars formed.
The lead author of the study, published in the Astrophysical Journal, explained, "This is the first time we have been able to identify parts of this primordial galaxy," which were named "Shakti and Shiva," after two Hindu deities whose union is said to have resulted in the creation of the universe.
The European Space Agency's Gaia probe, operational 1.5 million kilometers from Earth for a decade, delivered a three-dimensional map in 2022 detailing the positions and movements of over 1.8 billion stars.
This map revealed a cluster of stars dubbed "the old poor hearts" due to their great age, indicated by their low metallicity (a chemical index of a star's age) and their central location.
This discovery was a significant step for galactic archaeology, aiming to reconstruct the various epochs in the history of the Milky Way "in the same way archaeologists reconstruct the history of an ancient city," stated the Max Planck Institute in a release.
Thus, the model of the Milky Way's evolution resembles an "ancient central city surrounded by newer regions," according to the institute. However, "The further back we go in time and space, the blurrier the picture of the galaxy's history becomes," Malhan remarked.
Astronomers in 2022 explored this ancient core, analyzing a sample of 6 million stars for their chemistry and positions, notably using artificial intelligence.
This led them to identify two "stellar streams" (Shakti and Shiva), formed between 12 and 13 billion years ago in the early epochs of the Milky Way.
Surprisingly, the stars within these streams possess unusually high metal contents for their age, potentially indicating they originated from a previous generation of stars. As these predecessors died, they released chemical elements that "seeded" the interstellar gas from which the Shakti and Shiva stars formed.
Translation:
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