A team of astronomers has discovered the oldest stars ever seen, dating from before the Milky Way Galaxy formed, when the Universe was just 300 million years old.
The stars, found near the centre of the Milky Way, are surprisingly pure but contain material from an even earlier star, which died in an enormous explosion called hypernova.
These pristine stars are among the oldest surviving stars in the Universe, and certainly the oldest stars we have ever seen, said lead author Louise Howes from The Australian National University (ANU).
The discovery and analysis of the nine pure stars challenges current theories about the environment of the early Universe from which these stars formed.
The stars have surprisingly low levels of carbon, iron and other heavy elements, which suggest the first stars might not have exploded as normal supernovae, noted Howes, adding “Perhaps they ended their lives as hypernovae – poorly understood explosions of probably rapidly rotating stars producing 10 times as much energy as normal supernovae.”
The study is published in the latest issue of Nature.