Ancient Stars Provide New Estimate of Universe's Age, Challenging Hubble Tension Theories

• Astronomers have estimated the universe's age at approximately 13.8 billion years by analyzing the ages of 155,600 ancient stars in the Milky Way.
• This finding supports the standard cosmological model derived from the cosmic microwave background (CMB) and casts doubt on theories proposing a significantly younger universe (around 12.9 billion years).
• The research helps address the "Hubble tension" by suggesting that solutions relying on new early-universe physics may not be necessary to explain current expansion mismatches.

Methodology

• A research team led by Indranil Banik at the University of Portsmouth analyzed 247,103 stars.
• Data sources included high-resolution spectroscopy from China’s LAMOST telescope and precise distance measurements from the ESA Gaia satellite.
• Researchers filtered the stars for quality, ensuring they were metal-poor and chemically enriched according to predictions for early universe star formation.
• Final calculations focused on 155,600 stars, specifically those nearing the end of their lifespan where aging models are most reliable.

Implications for Cosmology

• The study produced an age estimate of 13.73 billion years for the oldest stars in the sample.
• When accounting for the time needed for the first stars to form post-Big Bang, the result aligns with the 13.8-billion-year estimate based on the CMB.
• Theories attempting to resolve the Hubble tension by suggesting a younger, 12.9-billion-year-old universe are challenged, as these stars would effectively predate the universe in such models.