Astronomers from Indiana University Bloomington report that a strange blue galaxy could solve a key puzzle.
A faint blue galaxy located some 30 million light-years from Earth could help answer a nagging question about the origins of the universe. According to a report from EarthSky, a team of astronomers from Indiana University at Bloomington has shown that Galaxy AGC 198691 has the least metal elements of any other ever observed.
The galaxy, nicknamed Leoncino, could offer a rare look into what the universe was made of around the time of its birth. According to study co-author John J. Salzer, “Finding the most metal-poor galaxy ever is exciting since it could help contribute to a quantitative test of the Big Bang. There are relatively few ways to explore conditions at the birth of the universe, but low-metal galaxies are among the most promising.”
The similarities between metal-poor galaxies and the early universe could help astronomers fine tune the current model of the Big Bang. One of the key provisions of the model involves the levels of helium and hydrogen at the Big Bang. Low levels of metal suggest that little stellar activity has occurred, allowing astronomers to peer closer toward the event.
“To find these low-metal galaxies… we must look far from home,” the authors said in a statement from Indiana University. “Our own Milky Way galaxy is a poor source of data due to the high level of heavier elements created over time by stellar processing, in which stars churn out heavier elements through nucleosynthesis and then distribute these atoms back into the galaxy when they explode as supernovae.”
The finding is also fascinating because Leoncino is relatively close to the Earth; it falls within the “local universe,” the area of space within 1 billion light-years. The dwarf galaxy is just 1,000 light-years in diameter and made of just a few million stars. Our Milky Way, on the other hand, contains as much as 400 billion stars.
A statement from Indiana University Bloomington describing the details of the study can be found here.