Methuselah Star (HD 140283)

The star earned the nickname "Methuselah Star" because early estimates of its age suggested it might be older than the universe itself. While refined measurements have resolved this paradox, it remains one of the oldest known stars at roughly 13.7 billion years old.

The star is located in the constellation Libra and is situated relatively close to Earth at a distance of about 190 light-years. Because of its proximity, astronomers have been able to study its properties in great detail.

It is classified as a metal-poor subgiant, meaning it contains very few heavy elements and is composed almost entirely of hydrogen and helium. This lack of metals indicates it was formed during a time before the universe had been heavily enriched by generations of supernovae.

Early calculations caused a stir by suggesting the star was older than the 13.8 billion-year-old universe, creating a massive cosmological paradox. However, subsequent observations using the Hubble Space Telescope refined its age to around 13.7 billion years, placing it safely within the age of the universe.