Fingerprints of oldest known star now a reality

In a major find, astronomers have successfully recorded the first fingerprints of the oldest known star in the universe - formed shortly after the Big Bang nearly 13.7 billion years ago.

"This is the first time that we have been able to unambiguously say that we have found the chemical fingerprint of a first star," said lead researcher Stefan Keller of Australian National University's School of Astronomy and Astrophysics.

The discovery has allowed astronomers to study the chemistry of the first stars, giving them a clearer idea of what the Universe was like when it was formed.

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 ancient star is around 6,000 light years from Earth, which is relatively close in astronomical terms. It is one of the 60 million stars photographed by SkyMapper in its first year.

"Finding such needles in a haystack is possible thanks to the ANU SkyMapper telescope that is unique in its ability to find stars with low iron from their colour," said Mike Bessell who worked with Keller on the research.

The composition of the newly discovered star shows it formed in the wake of a primordial star, which had a mass 60 times that of our sun.

The result may resolve a long-standing discrepancy between observations and predictions of the Big Bang, said the study published in the journal Nature.