In our galaxy’s galactic halo, there are 12 streams of stars orbiting. These burning balls of gas are actually being torn apart and their energy is absorbed into the Milky Way. In other words, they are the galaxy’s food source. Using the Anglo-Australian Telescope (AAT), a team has finally got to the bottom of these stars’ exact position, movements, and deterioration.
Why is this discovery so exciting?
The findings, published in Astrophysical Journal, are an important discovery as they provide all sorts of information about the dark matter present in the galaxy. This invisible force is what holds the stars in orbit throughout the galaxy, though it is extremely hard to study due to its minuscule size and strange properties.
“Think of a Christmas tree,” says co-author Professor Geraint F. Lewis. “On a dark night, we see the Christmas lights, but not the tree they are wrapped around. But the shape of the lights reveals the shape of the tree. It is the same with stellar streams – their orbits reveal the dark matter.”
Through this information, the history of the Milky Way’s star shredding and consumption can also be deciphered. “As our galaxy is getting older, it is getting fatter. This study gives us a snapshot of the Milky Way’s feeding habits, such as what kinds of smaller stellar systems it eats,” stated Professor Ting Li, a lead author of the paper.
Dark matter makes up approximately 85 percent of the matter in the universe. The exciting discovery is an important step in a deeper understanding of the world and universe around us.
Source study: Astrophysical Journal – S5: The Orbital and Chemical Properties of One Dozen Stellar Streams