Researchers have discovered the oldest known star that is believed to have formed right after the Big Bang, making it almost 13.7 billion years old.
"This is the first time that we've been able to unambiguously say that we've found the chemical fingerprint of a first star," said lead researcher, Doctor Stefan Keller of the ANU Research School of Astronomy and Astrophysics said in an Australian National University news release.
"This is one of the first steps in understanding what those first stars were like. What this star has enabled us to do is record the fingerprint of those first stars," he said.
The star is located only about 6,000 light years from Earth. The star was discovered by the ANU SkyMapper telescope at the Siding Spring Observatory, which has already photographed 60 million stars this year.
"The stars we are finding number one in a million," team member Professor Mike Bessell, who worked with Keller on the research said in the news release. "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 [color]."
The star is believed to have formed after a primordial star, which is 60 times more massive than our own sun.
"To make a star like our Sun, you take the basic ingredients of hydrogen and helium from the Big Bang and add an enormous amount of iron - the equivalent of about 1,000 times the Earth's mass," Keller said. "To make this ancient star, you need no more than an Australia-sized asteroid of iron and lots of carbon. It's a very different recipe that tells us a lot about the nature of the first stars and how they died."
Researchers used to believe primordial stars met their demise in huge explosions that threw iron into the far reaches of the universe. The newly-discovered ancient star does not show signs of iron pollution, but rather lighter elements like carbon and magnesium.
"This indicates the primordial star's supernova explosion was of surprisingly low energy. Although sufficient to disintegrate the primordial star, almost all of the heavy elements such as iron, were consumed by a black hole that formed at the heart of the explosion," Keller said.
