Astronomers of Australian National University discovered the oldest known star in the Universe on 11 February 2014. The discovery was published in the journal Nature.
The star, known as SMSS J031300.36-670839.3, is in the Milky Way galaxy and some 6000 light years from the Earth. The star was formed shortly after the Big Bang 13.7 billion years ago.
The star was discovered using the ANU SkyMapper telescope at the Siding Spring Observatory, which is searching for ancient stars as it conducts a five-year project to produce the first digital map of the southern sky. The discovery of the star was confirmed using the Magellan telescope in Chile.
The composition of the newly-discovered star shows it was formed in the wake of a primordial star, which had a mass 60 times that of our Sun. The iron content of the star was used to determine its age. The low iron content in the star suggests it was formed in a low energy explosion. This is a new discovery, as it means early supernovae were more varied in their energy than previously thought.
The discovery allowed astronomers for the first time to study the chemistry of the first stars, giving scientists a clearer idea of what the Universe was like in its infancy. The discovery will open the way for new approaches in examining the origins of the Universe.
This new discovery suggests early stars were much larger and would have burned more lithium than experts previously realised. The stars burn the lithium, they blow up, and don't emit much iron. This helps bring the lithium abundance into line with what the Big Bang theory predicts.
The Big Bang created a universe filled with hydrogen, helium and extremely small amounts of lithium. Iron, along with other elements, was forced in stars and supernovae. While modern stars were created from multiple star explosions and contain many different elements, older stars are more simplistic in terms of composition.