Astronomers have discovered the oldest known star so far, belonging to one of the first generations of stars formed shortly after the birth of the universe.
Star J031300.362670839.3 SIDS, as it was called, attracted the attention of astronomers because it contains a very small amounts of iron, a feature of ancient stars formed early on.
First generation of stars was formed immediately after the Big Bang, they contained, mostly, hydrogen, helium and small amount of lithium, explains Dr. Stefan Keller, author of the study published in Nature.
They were very massive stars with masses hundreds times bigger than the Sun’s mass, they had a short life, after a while, they exploded in supernovae and the material resulted from the explosion led to “enrich” universe with heavier chemical elements such as carbon, silicon and iron.
As soon as in the Universe appeared iron, small stars could arise so it took birth the second generation of stars, an example of such star is SIDS J031300.362670839.3. It has been identified (recently) and studied by researchers at the Australian National University.
Such ‘old’ stars gives astronomers the chance to study the conditions in the universe ago over 13.7 billion years. Stars are a kind of “time capsules”, they “store” elements that existed when they were formed, studying them, astronomers can understand what were the conditions at the time of their birth.
Now, Researchers collect and analyze data from large telescopes installed in Chile, in order to obtain a more detailed picture of the star, hoping that it will reveal more information about the first generation of stars in the universe.
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,
Dr Stefan Keller said.