After the Big Bang, the first stars started to form from the heating hydrogen gas roughly 13.7 billion years ago. Now, a team of astronomers led by Stefan Keller of The Australian National University have discovered one of the first stars.

The astronomers led by Dr. Keller’s operate the SkyMapper telescope at the Siding Spring Observatory in New South Wales. Identifying the stars was not easy. Since elements heavier than helium were forged in the cores of stars, the first ones consist mostly out of hydrogen. The scientists were able to identify this stars because of their low iron content, which influences their color. Utilizing this technique, SkyMapper is on 5-year survey studying the ancient Southern sky.

The discovery of a 13.7 billion years old star, thanks to its chemical signature, is a lifetime achievement for the team. The star is probably a second-generation star, and scientists will try to gather information about an older primordial star, which they believe could be made of hydrogen and helium and of 60 times bigger mass than our sun.

The stars we can observe are in a different phases of their life cycle, which also include death. It was long believed that old, or primordial, stars end their lives the same way other stars do – in a violent explosion where a supernova is created. It turns out, however, that deaths of old stars are relatively low-energy processes. The discovery of such old stars gives astronomers deeper understanding of the early life of our universe

Source: iflscience.com/space/astronomers-discover-oldest-known-star-universe#A42KOZosj7TOzKxG.99