The biography of our home galaxy may be due for some revisions. That’s because a bar-shaped collection of stars at the center of the Milky Way appears to be much younger than expected.
“These metal-rich stars are basically like fossil records of ancient stars that are telling the story of our home galaxy,” says Samir Nepal, an astrophysicist at the Leibniz Institute for Astrophysics Potsdam in Germany.
Stars with large proportions of metal elements are built from the remnants of stars that have since exploded, ejecting the metals they forged from lighter elements. Those spewed metals enrich the materials in the core of galaxies like the Milky Way, which is why a new generation of metal-rich stars can form only deep inside galaxies. The spinning bar at the center of the Milky Way then scattered some of those stars throughout our galaxy.
Using data from the European Space Agency’s Gaia space telescope, Nepal and colleagues reconstructed the development of the Milky Way bar through its influence on the distribution of metal-rich stars (SN: 5/9/18). They inferred the bar’s history, just as you might deduce where the batters stand in a baseball game by looking at the flight of the balls they hit, even if you can’t see home plate.
2023-12-13 12:00:00
Original from www.sciencenews.org