CAMBRIDGE, Mass., March 8 (UPI) -- U.S. astronomers say they found a star containing 6,000 times fewer heavy elements than Earth's sun, meaning it formed very early in the universe's history.
The scientists said the star, located about 290,000 light-years from Earth, supports the theory that Earth's galaxy underwent a "cannibal" phase, growing to its current size by swallowing dwarf galaxies and other galactic building blocks.
Researchers said the star -- which might have been among the second generation of stars to form after the Big Bang -- has a remarkably similar chemical makeup to the Milky Way's oldest stars.
"This star likely is almost as old as the universe itself," said astronomer Anna Frebel of the Harvard-Smithsonian Center for Astrophysics, lead author of the report.
Dwarf galaxies are small galaxies with just a few billion stars, compared with hundreds of billions in the Milky Way. The scientists said in the "bottom-up model" of galaxy formation, large galaxies attained their size over billions of years by absorbing their smaller neighbors.
The discovery by astronomers at the Harvard-Smithsonian Center for Astrophysics and the Observatories of the Carnegie Institution appears in the journal Nature.
