Utilizing an enormous catalog of Solar-like stars constructed by ESA’s Gaia mission, astronomers have discovered sturdy proof that our residence star traveled outward with 1000’s of stellar counterparts roughly 4 to six billion years in the past, providing new clues to the formation of the Milky Method’s central bar.
An artist’s impression of a migration of the Solar and its stellar twins from the middle of the Milky Method roughly 4 to six billion years in the past. Picture credit score: NAOJ.
“Whereas archaeology on Earth research the human previous, galactic archaeology traces the huge journey of stars and galaxies,” mentioned Tokyo Metropolitan College astronomer Daisuke Taniguchi and colleagues.
“For instance, we all know that our Solar was born round 4.6 billion years in the past, greater than 10,000 light-years nearer to the middle of the Milky Method than we’re in the present day.”
“Whereas research of the composition of stars help this principle, this has lengthy confirmed a conundrum to scientists.”
“Observations reveal an infinite bar-like construction at our Galactic middle which creates a corotation barrier, which makes it tough for stars to flee so removed from the middle.”
Of their analysis, the authors aimed to construct a big catalog of photo voltaic twins, stars whose stellar parameters are very near these of the Solar.
“Photo voltaic twins are outlined as stars with stellar parameters (i.e., efficient temperature, floor gravity, and metallicity) very near these of the Solar,” they mentioned.
“By performing differential analyses between stars with very comparable stellar parameters — photo voltaic twins in our case — one can obtain a particularly excessive accuracy within the measurements of stellar parameters and chemical abundances.”
The astronomers used knowledge gathered by ESA’s Gaia satellite tv for pc, a frightening trove of observations from two billion stars and different objects.
They created a listing of 6,594 photo voltaic twins, a group round 30 instances bigger than earlier surveys.
From this immense listing, they have been in a position to acquire essentially the most correct image thus far of the ages of those stars, rigorously correcting for choice bias of stars that are simpler to see.
Wanting on the distribution of ages, they seen a broad peak for stars round 4 to six billion years outdated: this consists of our Solar, and is proof for comparable stars of comparable age, positioned across the similar distance from the middle of our Galaxy.
Which means our Solar isn’t at its present place accidentally, however as a part of a a lot bigger stellar migration.
The invention sheds gentle not solely on the character of our Photo voltaic System, however the evolution of the Milky Method itself.
“The corotation barrier created by the bar construction on the Galactic middle wouldn’t enable for such a mass occasion,” the researchers mentioned.
“Nonetheless, the story adjustments if it was nonetheless being fashioned on the time.”
“The ages of our photo voltaic twins reveal not solely when the mass escape occurred, however the time vary over which the bar was fashioned.”
“The middle of the Galaxy is a far much less hospitable setting for the evolution of life than outer areas.”
“Our findings thus illuminate a key think about how our Photo voltaic System, and in flip our planet, discovered itself in a area of the Galaxy the place organisms might develop and evolve.”
The results have been printed March 12, 2026 within the journal Astronomy & Astrophysics.
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Daisuke Taniguchi et al. 2026. Photo voltaic twins in Gaia DR3 GSP-Spec. I. Constructing a big catalog of photo voltaic twins with ages. A&A 707, A260; doi: 10.1051/0004-6361/202658913
