All articles tagged with #radial migration
Astronomers mapped a clear boundary to the Milky Way’s star-forming disk at about 40,000 light-years from the center by analyzing stellar ages and using galaxy simulations; inside this radius star formation continues, while beyond it older stars migrated outward, creating a distinctive U-shaped age pattern.
Astronomers mapped the Milky Way’s star-forming disk and find that active star formation ends at roughly 40,000 light-years from the center; the Sun sits well inside this boundary at about 26,000 ly. The stellar age distribution forms a U shape—young toward the center and older beyond the edge due to radial migration where stars born closer in travel outward along spiral arms. Simulations suggest a sharp drop in star-formation efficiency at 40,000 ly, potentially linked to the Galaxy’s bar or disk warp. The finding relies on Gaia data plus ground-based spectroscopy from LAMOST and APOGEE and is published in Astronomy & Astrophysics.
Astronomers mapped the Milky Way’s star-forming disk by analyzing stellar ages with Gaia data and ground-based surveys (LAMOST, APOGEE) and simulations. They found the outer edge of active star formation at about 35,000–40,000 light-years from the Galactic Center, marked by a U-shaped age pattern where ages dip closest to the center and rise beyond the edge. Beyond this boundary, most stars migrated outward rather than formed in situ, explaining why older stars populate the far outer disk. This defines the true edge of the Milky Way’s star-forming region and highlights inside-out growth and radial migration as key Galactic processes.
Astronomers mapped ages for about 100,000 bright stars across the Milky Way’s disk and found that active star formation effectively ends at roughly 40,000 light-years from the Galactic center, creating a U-shaped age profile where younger stars lie inward and older ones outward. The outer stars likely reach those distances via radial migration along spiral waves rather than in situ formation. The boundary’s origin could relate to the Milky Way’s bar or disk warp, with Gaia data combined with ground-based spectroscopy (LAMOST and APOGEE) and simulations helping explain the phenomenon, though the exact mechanism remains under study.
The sun and our solar system are constantly moving through the Milky Way, orbiting the supermassive black hole at the galaxy's center. It takes around 230 million years for the sun to complete one trip around the Milky Way, and if its orbital pathway remained constant, it would have completed around 20 trips. However, the sun's orbit has likely changed over its lifetime due to radial migration, where stars are pushed along the galaxy's spiral arms. The sun was probably born closer to the galactic center and has migrated outward over billions of years. The exact number of times the sun has traveled around the Milky Way is uncertain, but it is believed to be more than the estimated 20 trips.
The sun and our solar system are not only orbiting the sun but also circling the supermassive black hole at the center of the Milky Way. It takes around 230 million years for the sun to complete one trip around the galaxy, but its orbit has not remained constant over its lifetime. The sun was likely born closer to the Milky Way's center and has migrated outward through a process called radial migration. This means the sun has made more trips around the galaxy than previously estimated. While it is currently in a fairly stable orbit, there is a possibility that the sun will continue to migrate outward in the future.