The universe continues to throw up surprises, and black holes are at its center. The largest planets discovered so far don’t seem to fit the usual story of how stars die. A new study suggests that these extreme objects may not form in a single collapse at all.
Instead, they can grow step by step within dense star clusters, where gravity continually pulls the objects into close contact. Scientists analyzing gravitational wave data from LIGO-Virgo-KAGRA believe that frequent mergers may be the real driver behind these giants, ScienceDaily reported. It is a chaotic and violent idea. Black holes collide again and again, slowly building something much larger than any star could ever make.
The more the data was studied, the more prominent this pattern seemed.
How black holes form, merge, and grow within dense spherical clusters
Globular clusters can be considered some of the densest parts of space. In this place, hundreds of thousands of stars are concentrated within a small radius, held together by gravity. According to Cardiff University, one example of such a globular cluster is the M80 star cluster, which is estimated to be 28,000 light-years from Earth.
The globular cluster region is highly unstable and dynamic.In such an environment, black holes cannot remain separated for a long period of time. Black holes move, interact with each other and merge. Scientists believe that such an environment could facilitate the merger of black holes through natural processes. The process itself is not smooth. It occurs over millions of years of gravitational interactions.
The study group analyzed data on 153 black hole mergers recorded in the GWTC4 catalog.
This database includes observations of gravitational waves caused by collisions of celestial bodies such as black holes.What scientists have found is a clear division between two types of black holes. One group appeared to have less mass, with slow and fairly regular rotations. They are thought to come from ordinary stellar collapse, where a massive star reaches the end of its life and forms a black hole.The second group looked completely different. These black holes were heavier and rotated faster. Its rotation directions also seemed random and not consistent. According to researchers, this is important evidence. This may indicate that these objects were not formed in a single event, but rather were built through multiple mergers within dense star clusters.
Why does the black hole mass gap exist and what it reveals about cosmic collisions
According to the study published in ScienceDaily, titled “The Universe’s Largest Black Holes May Form in Violent Mergers,” another interesting feature in the data is what scientists call a “mass gap.”
This is a range of black hole masses where, in theory, objects should not exist if they formed directly from collapsed stars.Stars larger than a certain size are expected to explode in such a powerful way that no black hole is left behind. This process, associated with pairwise instability, should create a gap around a certain mass range. However, the study identified nearby black holes about 45 times the mass of the Sun located in or near this gap.
This challenges old models of stellar evolution.The researchers point out that these heavy black holes may not have formed directly from stars at all. Instead, they may be the result of previous black hole mergers, which were built step by step into dense clusters where interactions were repeated.
How recurring black hole mergers build larger, faster-spinning cosmic objects
The concept of this model is relatively easy to understand, although the process itself is quite brutal. First, a black hole emerges from a dead star, which later transitions into a narrow cluster of black holes.
There, he finally encounters another black hole and unites with it. The existence of a new, larger black hole won’t stop here; In fact, the cycle could resume again, creating an increasingly massive and rapidly rotating black hole.It is thought that this phenomenon may give some clues about the peculiarities of supermassive black holes detected by gravitational waves, since their spin and mass patterns clearly indicate multiple collisions rather than the creation of one.
What this means for black hole research
This study, conducted by researchers from Cardiff University, adds a new layer to how scientists understand black hole growth. Gravitational wave astronomy is still a relatively young field, but it is already reshaping long-standing assumptions about the universe.It now appears that black holes may not just be the final stage of a dying star. In some cases, they could be part of a much longer chain of cosmic evolution within star clusters. A kind of slow assembly process driven by gravity, collisions, and time. It seems that the universe does not just create black holes. They also recycle them over and over again within some of the busiest environments.
