13.6 Billion Years Old Star Found
Astronomers in Australia on Sunday had announced that they have found the oldest star, that is 13.6 billion years old. This star was formed few hundred million years after the big bang.
Previously observed known oldest stars are around 13.2 billion years old, they are two stars discovered in 2007 and 2013.
This oldest star, the 13.6 billion old one, is actually in our own galaxy – Milky Way and around 6000 light years away from Earth. The star catalog list it by the number of SMSS J031300.36-670839.3
The oldest star was found using spectrography – the way of analyzing the star’s spectrum of light and decide which elements are in the star. The oldest star has very few amount of iron in it, comparing to our Sun, oldest star has only one millionth amount of iron.
Iron is a crucial element to decide the age of a star. Big Bang produced the universe with hydrogen, helium and trace amount of lithium. All other elements are forged by the stars. Some of them are forged when the star is burning and some of them are forged when the star ends its life with supernovae.
The age of stars or stellar objects can be determined by analyzing the amount of iron it has.
The iron content of a star is increased every successive birth, therefore when the iron amount is low in the star, we can determine that it is very old one.
The 13.6 billion years old star has just millionth of iron content comparing to our Sun and 60 times lesser than any other known stars.
The star is discovered using Australian National University’s SkyMapper telescope.
Australian astronomers says that the star was formed from the remnants of low energy supernova from star whose mass was roughly 60 times that of the Sun.