SYDNEY — Astronomers have discovered a red giant 3,500 light-years from Earth that could be one of the oldest stars in the cosmos, according to a paper published in the Monthly Notices of the Royal Astronomical Society.

Writing in a news release, researchers say the very first stars created by the Big Bang are believed to be extinct, but the red giant they spotted in the galactic halo is likely a descendent of those much older stars.

The red giant contains the least amount of iron ever detected, or 1.5 million times lower than that found in the Sun. Since metallic elements are created by ancient stars, an anemic star is likely to be much older than metallic stars.

The first stars were believed to be made of pure hydrogen and helium. When these stars die, they explode into supernovas and create metal elements. This explains why the red dwarf, a direct progeny of the first stars, contains so little iron.