Traces of the universe’s first stars discovered by researchers
Astronomers have found what they believe are chemical traces of the explosion that brought the first stars into existence 13.5 billion years ago.
Researchers from Italy’s University of Florence believe the study is the biggest clue yet as to what happened after the Big Bang.
This is a cosmological model that describes the universe’s earliest known periods and subsequent large-scale evolution. The Big Bang theory suggests that the universe started as a singularity and expanded rapidly, cooling and eventually forming the cosmos we observe today.
“These findings bring us one step closer to understanding the nature of the first stars that formed after the Big Bang,” the European Southern Observatory said of the Italian researchers’ study.
The researchers believe the first stars were different from the ones we see today and contained hydrogen and helium. They were potentially hundreds of times larger than the sun but quickly burned out.
Andrea Saccardi, a Paris University PhD, student who was part of the team, said: “For the first time ever, we were able to identify the chemical traces of the explosions of the first stars in very distant gas clouds.”
It was from this gas, researchers have said, that later stars formed and were longer lasting — containing heavier elements for the first time.
The team found three very distant gas clouds which they believe showed the universe at only 10 to 15 per cent of its current age. The clouds have very little iron but plenty of carbon and other elements, which was referred to by the Observatory as “the fingerprint of the explosions of the very first stars”.
Stefania Salvadori, of the University of Florence and a co-author of the study, said: “Primordial stars can be studied indirectly by detecting the chemical elements they dispersed in their environment after their death.”
The team used the European Southern Observatory’s Very Large Telescope in Chile to spot traces of the existence of the first stars.
It has been a busy period for skywatchers with the penumbral lunar eclipse set to occur on Friday, May 5, which will see the faint outer part of Earth’s shadow cast across the lunar surface. Click here for more details about this event and how to see it.
There is also the Eta Aquariid meteor shower, which has returned this month and is sending shooting stars across British skies. For more information, see our explainer here.