An international team of astronomers says it may have detected the signature left behind by one of the earliest stars to form in the universe.
Scientists have long theorized that a sample of those very early stars could have been giants hundreds of times as big as our sun, but hard evidence to support that model has been hard to come by.
In a study published in the journal Science, the astronomers report detecting the possible traces of just such an early giant stellar entity in the unique chemical composition found in a star in our Milky Way galaxy.
"This is quite a unique star, with a very peculiar chemical pattern that has never been found previously," says lead study author Wako Aoki of the National Observatory of Japan.
Chemical elements found within that star could have been created during the death throes of a star with extreme mass and possibly one of the first that formed after the Big Bang origin of the universe, the astronomers say.
If that's confirmed it could offer proof that some of the earliest stars in the universe were so big that when they died they did so in explosions so violent they affected the growth of the universe's earliest galaxies and their own stars, they say.
With up to 300 times the mass of our sun, their explosive deaths would have been unlike anything seen in our Milky Way today.
Such a giant explosion may have seeded the star the astronomers examined, known as SDSS J0018-0939, with its unusual mix of elements, the astronomers suggest.
The distant orange star is located around 1,000 light years away in our galaxy's stellar halo, a population of ancient stars surrounding the Milky Way's bright inner disk.
It probably formed out of a gas cloud whose chemical makeup was enhanced by the death of another star in what is known as a pair-instability explosion, as much as 100 times as violent as a usual supernova, which would have created elements as heavy as nickel.
The original big bang of the universe's creation would have produced only hydrogen and helium, setting the stage for giant cosmic explosions to create the heavier elements founds throughout the universe today.
Those elements ejected from the violently exploding stars out into the young universe then seeded gas clouds in their vicinity, helping them cool and then condense quickly to create a second generation of smaller young stars, some of which still exist in the universe today, the astronomers said.
