Galactic Archaeology Reveals Sun Joined Mass Migration of Solar Twins From Milky Way Core Billions of Years Ago

New research shows our Sun migrated 10,000 light-years from the Milky Way's core 4-6 billion years ago during the formation of the galaxy's central bar.

By: AXL Media

Published: Mar 12, 2026, 11:16 AM EDT

Source: Information for this report was sourced from Tokyo Metropolitan University

The Discovery of a Shared Galactic Journey

Researchers have uncovered significant evidence suggesting that our Sun did not reach its current position in the Milky Way by accident, but rather as part of a massive exodus of similar stars. By utilizing an unprecedentedly accurate catalog of stellar properties, a team led by Assistant Professor Daisuke Taniguchi has traced the movement of thousands of "solar twins"—stars with nearly identical temperatures and compositions to our own. This field of galactic archaeology has revealed that between 4 and 6 billion years ago, a vast cluster of these twins migrated from the crowded, high-energy core of the galaxy to the more stable outer regions where our solar system currently resides.

Solving the Mystery of the Corotation Barrier

For years, scientists have faced a conundrum regarding the Sun’s origin, as it was born roughly 10,000 light-years closer to the galactic center than its current location. Under normal circumstances, an enormous rotating bar-like structure at the center of the Milky Way acts as a "corotation barrier," a gravitational wall that makes it extremely difficult for stars to migrate so far outward. The team from Tokyo Metropolitan University and the National Astronomical Observatory of Japan analyzed data from the European Space Agency’s Gaia satellite to understand how our Sun bypassed this obstacle. The findings suggest that the barrier was not yet fully established when the Sun and its twins began their journey.

Utilizing the Power of the Gaia Satellite

The research utilized a massive trove of observations from the Gaia mission, which monitors nearly two billion objects across the sky. From this data, the team curated a specialized catalog of 6,594 solar twins, a collection approximately 30 times larger than any previous survey. By carefully correcting for selection bias—the tendency for brighter or closer stars to be more easily seen—they were able to obtain a high-precision picture of stellar ages. The distribution showed a distinct peak for stars aged 4 to 6 billion years, aligning perfectly with the age of our Sun and confirming that a mass migration event was underway during the Sun’s formative years.