A group of ancient stars have been spotted near our sun, hinting to astronomers that our galaxy is billions of years older than we first thought.
Most of the more than 100 bilion stars in the Milky Way rest on an invisible “halo” that rotates around the supermassive black hole at the center of the galaxy, which scientists previously estimated had formed about 8 to 10 billion years ago. However, new insights into these primordial stars by the European Space Agency’s Gaia spacecraft spacecraft suggest that Planet Earth’s cosmic community could be over 13 billion years old.
Researchers with the Leibniz Institute for Astrophysics Potsdam (AIP) in Germany officially announced their discovery on July 31 following the publication online of their unreviewed report earlier this year.
The whole of our measurable universe is thought to be about 13.8 billion years old, meaning the Milky Way would have formed during the first billion years of existence as we know it, per the study.
“These ancient stars in the disc suggest that the formation of the Milky Way’s thin disc began much earlier than previously believed, by about 4-5 billion years,” said lead study author Samir Nepal in a statement.
Machine learning helped scientists calculate new data into some 800,000 stars in our solar neighborhood, including their surprising metal content.
At the beginning of time, our universe was predominantly composed of hydrogen and helium — and most old stars are a reflection of this environment. However new data revealed that some of the oldest celestial crumbs are more metallic than previously thought possible —- with twice the metal content of much of our relatively young, 4.6-billion-year-old sun.
The discovery of rapid metal enrichment in the early phase of galactic growth has changed how scientists are mapping our galaxy’s history.
“This study also highlights that our galaxy had an intense star formation at early epochs leading to very fast metal enrichment in the inner regions and the formation of the disc,” Nepal said.
