Astronomers determined the precise boundary of the Milky Way

An international team of astronomers has determined the precise boundary of the Milky Way's star-forming disk. The distance from the center of the Milky Way to the boundary of its star-forming disk is 40,000 light-years, MIR24 reports.

In their research, the scientists measured the ages of bright giant stars and combined these data with modeling of galaxy evolution. This approach revealed a distinct "U-shaped" pattern in the ages of stars, marking the outer boundary of active star formation in our galaxy.

Stars in a galactic disk are known to evolve unevenly. Star formation begins in dense central regions and spreads to the outer regions over billions of years. As a result, stars in the outer regions of galaxies are significantly younger than those in the center.

The Milky Way only partially conforms to this pattern. The study found that the age of stars decreases with distance from the center, as expected. However, at a distance of approximately 35,000-40,000 light-years from the galactic center, this trend reverses. Beyond this region, stars become older. Scientists have determined that the region where the youngest stars are located is the boundary of the Milky Way.