- BBC News World
A team of researchers from the Max Planck Institute for Astronomy (MPIA) has identified, in the central regions of our galaxy, the “poor old heart of the Milky Way”.
These were the words they used to refer to a Star residents formed in the early history of the Milky Way, more than 12.5 billion years.
Astronomers made this discovery by analyzing the latest information from the European Space Agency’s Gaia mission, using a neural network to extract mineral Two million bright giant stars in the inner regions of our galaxy.
Metallicity is the amount of chemical elements heavier than helium contained in a star’s atmosphere (the less metallic it is, the older the star).
On a sky map, these stars appear to be concentrated around the center of the galaxy.
The distances given by Gaia (via the parallax method) allow a 3D reconstruction showing those stars confined within a relatively small region around the center, about 30,000 light-years across.
The discovery of these stars, as well as the properties observed, confirm cosmological simulations of the history of our most ancient galaxy.
As the researchers explain in the study, these simulations predicted where ancient stars might be located.
To perform the analysis, the astronomers resorted to machine learning methods.
In this particular case, the neural network was trained using the selected Gaia spectra as input: the Gaia spectra for which the correct answer, metallic, was already known from another study.
The neural network was able to derive precise and accurate minerals even from stars it had never encountered before.
While the insights gained from analyzing the Gaia data are groundbreaking in that they prove the continued existence of the “poor old heart” of our Milky Way, the discovery raises new questions, such as the Milky Way’s parent galaxy for both stars belonging to this central region.
The researchers are confident that they will be able to answer this question and others in the future.
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