Scientists have suspected for some time that the Sun formed much closer to the center of our galaxy than it is now. However, only recent studies of its “twins” have confirmed this.
Where was the Sun born?
Recently, Japanese scientists published a study in the journal Astronomy and Astrophysics presenting evidence that our sun was born approximately 10,000 light-years closer to the center of the Milky Way than its current location.
It is worth remembering that our star is not stationary. It moves around the center of the Galaxy in an orbit that currently takes about 250 million years to complete. However, this is such a long period of time that it was even established on the basis of observations made over a relatively short period.
Therefore, no one is certain that it also flew in the same orbit before. Moreover, comparing the chemical composition of other stars with our sun confirms the theory that it was born in the inner parts of our galaxy and then migrated outward.
However, until now, there has been a major obstacle standing in the way of this theory. More precisely, a barrier called the bulge, located in the center of the Milky Way. Theoretically, it should prevent such migrations.
Group escape
And here, the European Space Agency’s Gaia satellite came to the help of scientists with its enormous database of celestial bodies. This is where scientists began collecting data on “twins” of the Sun, i.e., stars that are similar to the Sun in terms of their chemical composition and physical characteristics.
There were 6,594 of them. Such a large sample allowed us to estimate their age, orbits, and chemical composition. And this picture confirms that approximately 4–6 billion years ago, a huge migration occurred from the center of the Galaxy.
In other words, the Sun did not escape from there alone, but as part of a large group of stars. Of course, this did not happen all at once, and specifically with our star, it happened in the first hundreds of millions of years of its existence.
As for the bulge, or barrier, in the center of the Milky Way, its problem is probably quite clear. This structure simply did not exist several billion years ago. In spiral galaxies, they only form at a certain age.
According to phys.org
