While the Milky Way is beautiful to look at in the pure, natural night sky, that beauty may be only skin deep. Our galaxy may actually be a celestial bully in our universal schoolyard.
According to new research from the Harvard-Smithsonian Center for Astrophysics, of the 11 farthest stars in our galaxy, some were likely swiped from a nearby galaxy. That’s right: 300,000 light years away, some of our galaxy’s stars are the cosmic equivalent to stolen money from a helpless nearby galaxy.
The scrawny, bespectacled whelp that is the victim of the Milky Way’s wedgies and noogies? Why, it’s little old Sagittarius, a helpless dwarf galaxy that happens to be the second closest to our galaxy. Marion Dierickx and Avi Loeb, a graduate student and a Harvard theorist respectively, ran computer simulations that tracked Sagittarius’ movements. Investigating the dwarf galaxy’s velocity and inclination over the past 8 billion years, the team observed that the Milky Way’s pinched about 5 or 6 stars from Sagittarius as Sagittarius orbited past. But the Milky Way has been revealed to be a serial bully, taking another 5 stars from other playground wimps who don’t have the gravitational pull to defend themselves.
Sagittarius though, needs particular attention from the school guidance counselors. Dierickx and Loeb hope to discover more stolen stars at the Apache Point Observatory in Sunspot, New Mexico. The Milky Way has taken 90 percent of Sagittarius’ dark matter, and about one third of its stars over time, and will continue to do so each time they pass each other in the locker-adorned hallway that is our universe.