Astronomers track down oldest known star in the universe
Scientists pull a needle out of a haystack and identify a star that dates back to shortly after the Big Bang.
According to the Big Bang theory, the universe was formed 13.7 billion years ago. A star that formed shortly after that event was recently discovered by astronomers from the Australian National University, an especially impressive find considering it was weeded out from among 60 million stars photographed by the SkyMapper telescope in its first year of operation.
The discovery is giving scientists a peek at what the universe was like as a baby. SkyMapper is at the start of a five-year mission to map the southern sky. It found the ancient star at a location of about 6,000 light-years from Earth, which is really pretty close in terms of distances across the universe. It is part of the Hydrus (water snake) constellation and has been given the name SMSS J031300.36-670839.3, though its astronomy buddies call it SM0313 for short.
"This is one of the first steps in understanding what those first stars were like. What this star has enabled us to do is record the fingerprint of those first stars," said astronomer Stefan Keller. Keller said the second-generation star's formation required significantly less iron than did the formation of stars like the sun. It was seeded from a single supernova from a first-generation star.
The star stood out from the crowd thanks to the SkyMapper telescope's ability to locate stars with low-iron content based on their color. The findings were confirmed by researchers using the Magellan telescope in Chile. The research was published in the journal Nature.
The low-iron composition of SM0313 gives scientists a lot to consider about how the very first stars may have died in low-energy supernova explosions, rather than in very violent explosions as previously hypothesized. It's a rare glimpse into the heart of the universe's origins.