The globular star cluster Palomar 5, which is about 80,000 light-years away in the constellation Snake, may not look quite as good as some of its other globular celestial colleagues. It is faint, and of the 150 known globular clusters known to astronomers in our galaxy, it is one of the least massive representatives with few stars. The density of its star is barely higher than that of our stellar neighborhood – after all, we are not in a globular mass.
However, Palomar 5 is accompanied by stellar streams, that is, stars that were ejected from the globular cluster at an earlier point in time. A research team describes how Palomar 5 can access these stellar currents in Nature Astronomy. According to this, black holes could have caused stars to be ejected from the globular cluster. Within a billion years, a spherical star can consist of no more than one black hole.
How Palomar 5 Reached Its Star Streams
Stellar currents are loose groups of stars moving in the same direction and at similar speeds. Astronomers know them in several ways: for example, they arise when our own Milky Way dwarf galaxy is torn apart again by tidal forces. In recent years, researchers have also discovered thinner and smaller star streams that barely indicate an entire dwarf galaxy. However, most of these smaller stellar currents do not provide any clues to their origin.
The globular cluster Palomar 5 was an interesting research object for Marc Gillis of the University of Barcelona and colleagues because it is accompanied by two such stellar currents. It can therefore be assumed that streams of other thin stars also originate from globular clusters. but how?