Scientists believe that our galaxy, the Milky Way, was created after many mergers, with smaller galaxies and clusters of stars. Some mergers were very recent, and scientists can still detect the clusters of stars orbiting the galaxy. But in time, interactions with the rest of the stars will probably slowly disrupt the structures of clusters.
So it’s kinda off that they’ve found the remains of a cluster that’s made out of some of the oldest stars out there. So the question is: how did it stay intact for that long?
ESA’s Gaia mission has come with numerous details about our galaxy. It showed a billion objects dozens of times, which was enough to estimate their position and motion in the galaxy. This kind of map has helped us in finding the structures from our galaxy. They put the basis on the fact that there are groups of stars that are not only close to each other, but that also move in the same direction.
This entire process is useful – there is even a software algorithm that’s called STREAMFINDER, that can identify them. With the help of this software, we’ve discovered the C-19 stellar stream, which is a group of stars that’s moving together in the galaxy.
Clusters are made out of stars that are similar in ages. We can check and see if they were formed at the same time by checking the content of heavier elements. The heavy elements were produced by earlier stars. After they’ve measured the heavy elements, they came to an interesting conclusion: they were all quite similar, with the exception of one. This showed that the group is actually the remnant of a cluster. Moreover, the results showed that there was an unusually low amount of heavy elements there.
