The fascination for celestial objects has intrigued us since millennia. Our ancestors described the band of stars as a river, an ocean of milk, a path, among many other things.
Observations, studies and debates have led to many discoveries about the objects in the heavenly sky, which were presumed to be part of our universe.
Even until the early 1920s, astronomers thought that the Milky Way, our galactic home contained all the stars in the universe. In fact, it is one among the millions of galaxies known to man. The ‘Milky Way’ derives its name from the spiral band of stars and gas clouds that stretches across the sky as seen from Earth.
Understanding the structural layout of the Milky Way has been a challenge, as the spiral galaxy expands about 100,000 light-years across.
The Milky Way appears as a band because its disk-shaped structure is viewed from within. Our solar system sits on the outer edges of one arm of the disk, which makes it humanly impossible to see beyond the band of light. Like early explorations helped map the continents and water bodies of our globe, astronomers are busy mapping the spiral structure of the Milky Way.
According to a new discovery, a new group of stars at the centre of our galaxy could have migrated from another cluster of stars or a dwarf galaxy, approximately located 320,000 light-years away.
The new ground-breaking study published in The Astrophysical Journal Letters, an international consortium of astrophysicists, including scientists from the University of Surrey detail how the newly discovered star cluster with different characteristics than their neighbours found in the milky way’s Nuclear Star Cluster (NSC).
Using state-of-the-art high-resolution computer simulations, the team explained how this group of stars came to be located at the centre of our galaxy.
According to their calculations, this group of stars are leftovers from the migration of a massive star cluster that formed a few light-years away from our galaxy. The team also noted that the group of stars could possibly have originated from a dwarf galaxy located 320,000 light-years away from the galactic centre.
Most of the evidence points towards an accretion event that happened 3-5 billion years ago and Cluster stars were deposited in the region and were discovered based on their peculiar velocities and low metal content.
“This discovery may be the smoking gun evidence that the Milky Way has been accreting star clusters or dwarf galaxies,” said Dr Alessia Gualandris, senior lecturer in physics from the University of Surrey.