HD 140283, commonly known as the “Methuselah Star,” is one of the oldest known stars in the universe. Located approximately 190 light-years from Earth in the constellation Libra, it has been the subject of extensive study due to its age and composition.
Age Estimates
Initial studies, including a 2013 analysis using the Hubble Space Telescope, estimated HD 140283’s age at about 14.46 billion years, with an uncertainty of ±0.8 billion years. This posed a paradox, as it appeared older than the universe itself, which is estimated to be 13.8 billion years old.
Subsequent research aimed to resolve this discrepancy. A 2021 study utilizing updated stellar models and interferometric data revised the star’s age to approximately 12.0 ± 0.5 billion years. Another study in 2024, incorporating tailored chemical abundances, estimated its age at 12.3 billion years. These findings align HD 140283’s age with the current understanding of the universe’s timeline.
Significance
HD 140283’s extremely low metallicity indicates it formed shortly after the Big Bang, before heavier elements became widespread. As a Population II star, it provides valuable insights into the early universe’s conditions and the formation of the first stars.
In summary, HD 140283 is estimated to be between 12.0 and 12.3 billion years old, making it one of the oldest stars known, yet consistent with the age of the universe.
