A large part visible from Earth stars are the remnants of one of the clusters.
It is noted that using the Gaia telescope, astronomers were able to create the most accurate three-dimensional map of the milky Way. Stars tend to form clusters, but in this condition they remain for a long time – average congestion of “lives” only a few hundred thousand years. To keep the stars together, you need a huge mass, providing sufficient gravitational attraction. Even a small galaxy orbiting the milky Way, can be torn apart by its gravity. It is because of such deformation of the spiral and turn into a long “streams” of stars orbiting around the galaxy core.
Use the Gaia system, the researchers were able not only to obtain the coordinates of each star, but also to calculate their speed. As a result, the astronomers saw that the stars don’t move randomly, but in the form of a single stream, which still bears the traces of the past accumulations.
The flow is about 200 parsecs in width and 400 parsecs in length, and its age is estimated at one billion years. This means that he has already made four full revolutions around the Solar system (one turn requires 230 million years). This time is enough to accumulation of the formed flow.
Most of these stellar streams known today, is located outside the galactic disk and much larger in size. However, the location within the galaxy makes this particular thread a very valuable object for study, and even a useful tool. With its help, for example, you can explore the limits of the distribution of stars within the milky Way mass.