- Astronomers suggest the sun might have migrated from near the central bar-shaped nucleus of our Milky Way galaxy.
- Scientists studied 6,594 solar “twin” stars, using Gaia data. Many share the sun’s age (about 4–6 billion years) and appear to have migrated outward from the galaxy’s inner regions together.
- The sun eventually took up residence in a quieter part of the galaxy, where planets (and life) could develop with fewer threats.
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Our sun might be a migrant
Astronomers have long thought our sun was born closer to the center of our Milky Way galaxy than it is today.
The stumbling block to that idea has been the Milky Way’s huge central bar, which is essentially a massive gravitational engine. The galaxy’s central bar creates its own high-pressure, high-energy environment, where stars are being born and dying, and where energetic events like supernovas happen frequently. So it’s not a nice, quiet part of the galaxy for the founding and evolution of life.
Previous studies had shown the gravitational pull of this bar served as a barrier for escaping stars. But now a new study from Tokyo Metropolitan University – and reported by EurekAlert on March 12, 2026 – suggests that, as the central bar was forming somewhere between 4 and 6 billion years ago, it triggered both star formation and a wave of outward migration for stars … maybe including our sun.
How do we know?
Assistant professors Daisuke Taniguchi at Tokyo Metropolitan University and Takuji Tsujimoto at the National Astronomical Observatory of Japan led the new studies. They looked at stars that are similar to our sun – a G-type star – in terms of temperature, composition and surface gravity. Altogether, the survey included 6,594 of these virtual twins to our sun. That was out of the overall observations of 2 billion stars.
The data came from the European Space Agency’s amazing Gaia spacecraft. Gaia did what’s called astrometry. In other words, it obtained precise measurements of the positions of stars, over and over again. In this way, it revealed the movement of stars in our galaxy for more than a decade. The data showed there was a mass movement of stars, out of the turbulent inner galactic regions to more serene pastures.
Out here, farther from our galaxy’s core and its central bar, our sun now resides in a quieter part of the galaxy. And this could have big implications for why life could arise on Earth, and possibly on planets around similar stars in our neighborhood.
The researchers published two new papers in the peer-reviewed journal Astronomy and Astrophysics on March 12, 2026.
Our current place in the Milky Way
The sun and solar system lie about 25,000 light-years from the center of the Milky Way. And the central bar in the Milky Way extends some 10,000 to 15,000 light-years from its center. The 4.6-billion-year-old sun is in the Orion-Cygnus Arm, or Orion Spur, a minor spiral arm of the Milky Way galaxy.
The new study suggests our sun began its life in the galaxy at more than 10,000 light-years nearer to the galactic center than we are today. That would have put us close to the central bar.
But the central bar has a gravitational effect that scientists call a corotation barrier. Basically, its pull of gravity makes it hard for stars to travel far away from the bar. Enter the new study. It suggests the bar wasn’t fully formed until after the sun – and thousands of similar stars – made their escape.
Migrating to a safer neighborhood
The scientists who conducted the new study looked at a notable concentration of stars that are around 4 to 6 billion years old, similar in age to our sun. And they all currently inhabit a region of the galaxy that’s about the same distance from the center as we are.
The scientists concluded that the age and locations of these stars are evidence of a stellar migration. They said these stars and our sun were able to escape the gravity of the still-forming bar region. The stars made a mass exodus from a region that was, coincidentally, hostile to the formation of life.
Afterward, our sun and its planets – along with thousands of similar sibling stars – came to live in a quieter galactic neighborhood. It’s a region of the Milky Way where life was able to – at least once – evolve in relative peace.
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A new view of the heart of the Milky Way
By the way, researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile recently took a stunning new, detailed image of a molecular cloud feature in the heart of the Milky Way.
They captured the huge image in millimeter radio wavelengths. It revealed new details of a chaotic gaseous region with massive stars that orbits the supermassive black hole in our galaxy’s center. See it here, or watch the video below.
This brief video gives you a look at the new image of the Milky Way center taken in radio wavelengths. It’s the largest image the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile has ever taken. Video via ALMA (ESO/ NAOJ/ NRAO)/ S. Longmore et al. Background: ESO/ D. Minniti et al.
Bottom line: A new study suggests the sun might be a migrant that was born in the inner galaxy and journeyed outward. Researchers believe it made that crossing in the company of many other stars similar to our sun.
Source: Solar twins in Gaia DR3 GSP-Spec I. Building a large catalog of solar twins with ages
Source: Solar twins in Gaia DR3 GSP-Spec II. Age distribution and its implications for the Sun’s migration
Via EurekAlert