While we will never know exactly what happened during or after the Big Bang that formed our universe, scientists are beginning to gather data about the the very first generation of stars formed after the initial super-explosion that set everything into motion.
These first stars are known as Population III stars, and astronomers have described them as the “turning point for the universe”, as they took the circulating ultra-hot gases and converted them them into the heavier elements such as carbon, oxygen, iron, nitrogen and the metallic elements.
More on the first stars
The first stars in the universe were huge gas giants, several hundreds of times larger than the sun. These first stars also burned hot, bright and relatively fast compared to our sun. Astronomers say that these earliest stars likely burned out after just two million years or so, which means it will be pretty difficult to learn a whole lot more about them.
New research provides more information about Population III stars
A team of researchers led by David Sobral from the Institute of Astrophysics and Space Sciences in Portugal has found strong evidence of Population III stars in a galaxy 13 billion years away and 800 million years after the Big Bang.
The study was published in The Astrophysical Journal on June 4th 2015.
Based onm observations from the European Southern Observatory’s Very Large Telescope, with an assist from the Subaru Telescope and the Hubble Space Telescope, the team found a number of very bright, young galaxies as part of a wide survey of distant galaxies A galaxy they named CR7 caught their attention as it was by far the brightest galaxy found at this stage of the universe’s post Big Bang expansion.
CR7 also had a strong ionized helium signature, and showed no sign of heavier elements — almost exactly what you would expect to see if there were numerous Population III stars.
“The discovery challenged our expectations from the start, as we didn’t expect to find such a bright galaxy,” Sobral explained. “Then, by unveiling the nature of CR7 piece by piece, we understood that not only had we found by far the most luminous distant galaxy, but also started to realise that it had every single characteristic expected of Population III stars. Those stars were the ones that formed the first heavy atoms that ultimately allowed us to be here. It doesn’t really get any more exciting than this.”
Of interest, the team’s survey also discovered blue and red clusters of stars, which would suggest that Population III stars did not all form at once, but rather were created in waves. The researchers also observed what they believe to be the final wave of Population III stars coexisting next to regular stars. They note this means Population III stars may not be quite so rare and only found in the farthest, dimmest galaxies, but can also be found in galaxies that are close enough for more detailed observation of this first generation of stars..