An Old Friend

Unless you are a Young Earth Creationist (I’m looking at you Ken Ham), you probably know that the Universe is really old. Really, really old. About 13.8 billion years old to put a number on it.

Funnily enough, that makes it the oldest thing there is, but the prize for second place has been pretty hotly contested. Scientists have just awarded that place to a newly discovered star which they believe is 13.7 billion years old.
Those of you without short term memory loss will realise that that means it formed extremely soon after the Big Bang. For comparison, the Sun formed only 4.6 billion years ago.

The scientists were able to identify this star’s age thanks to its colour. In the same way that a fire can change colour depending on what is burning, the colour of a star can change depending on what it is made of.
Immediately after the Big Bang, practically the only matter there was to form stars was hydrogen and helium. As time went on, the first stars that formed turned the hydrogen and helium into other elements through nuclear fusion. These other elements could then go on to contribute to forming newer stars.

In this case, scientists were looking for the absence of iron in stars. Iron is the very last step in the nuclear fusion process, so the less iron there is in a star, the earlier it formed.
Finding and observing these stars is important in helping us understand the early universe and how the different elements were formed and spread throughout the universe, eventually leading to the formation of our own Sun, the Earth and all of us.
And the best part? Did I mention that the scientists who discovered this star are all from the ANU, led by Dr Stephan Keller from the Research School of Astronomy and Astrophysics? Take that, University of Melbourne!

That one. That’s the oldest.