Summary: Researchers found a few thousand strange young stars at the edge of our galaxy, the Milky Way, and concluded that these had formed from material bitten off of the Large and Small Magellanic clouds, a pair of dwarf galaxies that the Milky Way will eventually devour.
Original author and publication date: Rafi Letzter – January 9, 2020
Futurizonte Editor’s Note: If in our galaxy there are alien stars, could it be possible then that there is also alien life?
From the article:
The stars stood out in their distant corner of the Milky Way because that region isn’t producing many new stars these days. Unlike at the livelier, denser galactic center, most of the available fuel in the far reaches has already been used up. But analysis showed that these stars were relatively young.
“[This region is] really, really far away,” Adrian Price-Whelan, a research fellow at the Flatiron Institute’s Center for Computational Astrophysics in New York City and lead author of the Dec. 5 paper, said in a statement. “It’s farther than any known young stars in the Milky Way, which are typically in the disk. So, right away, I was like, ‘Holy smokes, what is this?'”
Further analysis showed that the stars seem to be made of unusual ingredients given their segment of the galaxy. The bands of light that reached Earth suggested that at least the 27 brightest stars in the cluster had unusually low metal content, indicating that the material that produced them came from outside the Milky Way.
The likeliest culprit, according to the second paper: the leading arm of the Magellanic Stream, a cloud of gas extending from the Magellanic Clouds toward the Milky Way that isn’t dense enough with gas to produce stars on its own.
What likely happened, the researchers concluded, is that gas from the stream at some point passed through the Milky Way, creating ram pressure (a type of shock wave) as the streaming gas collided with native Milky Way gas. That ram pressure, combined with the Milky Way’s gravity, compressed some of the Magellanic Stream gas enough that it clumped together under its own gravity. Once that happened, some of the clumps of gas got dense enough to form stars, leading to the unlikely presence of young, low-metal stars in the region.