Chinese scientists have discovered four previously unknown groups of scattered star clusters in the Milky Way. Some of them were born from the same giant molecular cloud. And the root cause of this process was the outbreak of just a few supernovae.
Ancient scattered clusters
Scientists from the Xinjiang Astronomical Observatory, along with their colleagues from other institutions of the Chinese Academy of Sciences, recently discovered several previously unknown groups of ancient star clusters. An article published in the journal Astronomy & Astrophysics revealed the secret of their birth.
All known star clusters are located in our galaxy, and they are truly ancient. Stars that are born together eventually fly apart in all directions and form a scattered star cluster, which then disintegrates completely, but the relationship between the stars can still be traced, and that is exactly what scientists have done.
In total, astronomers discovered several dozen star clusters that were so old that they had not been noticed until today. However, scientists have now not only discovered these objects, but also determined that they are grouped into four separate systems. At least two of these groups were formed from the same molecular cloud.
Feedback
Giant molecular clouds are clusters of cold gases formed by supernova explosions and can stretch across space for hundreds of light years. The most interesting thing about the new study is that scientists have proven the mechanism of formation through feedback for previously unknown clusters.
It all began with the birth of several extremely massive stars in a cloud — a phenomenon quite common in the early stages of the universe’s evolution. These stars went through all stages of their development in just a few million years and ended their lives in supernova explosions.
The shock waves caused by these explosions increased the local density of the cloud, initiating the formation of new stars. They also evolved and exploded rapidly, further accelerating the process — to the point of forming entire star clusters. This mechanism is called feedback.
It is also interesting that scientists were able to prove all this. They traced many old pulsars. They found among them those that should be located at the site of these clusters’ formation, meaning they could be remnants of the supernovae that created them.
According to phys.org
