MIT researchers discover oldest stars in universe

Researchers at Massachusetts Institute of Technology (MIT) in the US have identified three of the oldest stars in the universe, according to the school’s physics department.

The stars are thought to have emerged during the early stages of galaxy formation, 12 to 13 billion years ago, around the time when the first galaxies were taking shape, it said.

Using data collected from the Magellan-Clay telescope in Chile, researchers analysed the stars' spectra to determine their chemical composition and age.

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Researchers characterised the stars based on their low abundances of certain chemical elements, such as strontium and barium. The stars were also found to exhibit retrograde motion, indicating they were once part of smaller dwarf galaxies that merged with the Milky Way.

Located in the Milky Way’s halo -- the cloud of stars surrounding the main galactic disk -- the stars are referred to as SASS stars, or Small Accreted Stellar System stars.

The discovery is expected to offer significant insights into the early stages of galaxy formation and the evolution of the universe.