What To Know
- About thirty years ago, astronomers discovered a group of about a hundred stars, known as the S cluster, orbiting very close to the heart of the supermassive black hole Milky WaySagittarius A* (Sgr A*).
- In a recent study published in the journal Astronomy and Astrophysicsresearchers therefore analyzed the motions of YSOs and some S stars to understand their orbits around Sgr A*.
- This hypothesis is supported by the observation that S stars and YSOs appear to orbit in a thin, well-defined disk around the black hole, suggesting some kind of regulatory mechanism within the systemThis behavior could also be related to gravitational interactions between the stars themselves, as well as with the gas and dust present in the region.
Inexorably drawn by the enormous gravity of the supermassive black hole at the center of the Milky Way, young stars are moving at dizzying speeds near this cosmic singularity. Contrary to the appearance of stellar chaos, a new study reveals that these objects follow remarkably ordered trajectories, similar to the movements of swarms of insects such as bees. These findings open new perspectives on stellar dynamics near supermassive black holes.
The Riddle of the Stars S
About thirty years ago, astronomers discovered a group of about a hundred stars, known as the S cluster, orbiting very close to the heart of the supermassive black hole Milky WaySagittarius A* (Sgr A*). These stars S as they are called are surprisingly young (less than a hundred million years old) and are located only a few light-years away from this black hole. Its intense gravity then propels them at speeds exceeding the 3.5 million km/habout five times faster than the Sun’s motion through our galaxy. The presence of these young stars in the vicinity of a supermassive black hole has long intrigued astronomers. Current theories suggest that only the oldest stars should be so close to a black hole, which is clearly not the case here. The discovery of these objects has therefore raised crucial questions about stellar dynamics and star formation processes in extreme environments.
The strange behavior of young stellar objects
Over the past decade, scientists have also spotted about a dozen additional objects mixed in with the S stars orbiting Sgr A*. These entities, called young stellar objects (YSO), are star precursors still surrounded by clouds of gas and dust. They are in a phase where they are accumulating material and beginning to shine, but have not yet fully formed into adult stars. Again, their presence near a supermassive black hole challenges current models that did not predict the formation of such stars so close to such a turbulent region. In a recent study published in the journal Astronomy and Astrophysicsresearchers therefore analyzed the motions of YSOs and some S stars to understand their orbits around Sgr A*. Using advanced modeling techniques and precise observations, they then discovered hidden patterns and regularities in these movements which appear chaotic at first glance, but reveal a subtle organizationsimilar to swarms of bees.
Scientists have identified about a hundred S stars around Sgr A*. Credits: Eckart group, Ph1-UniKoeln
A phenomenon that is still not understood
The discovery of this organized behavior among young stars and YSOs around Sgr A* is a major advance in our understanding of stellar dynamics near supermassive black holes. Scientists are still unaware of the precise causes of this organized swarming, but it is highly likely that The gravitational influence of Sgr A* plays a crucial role. This hypothesis is supported by the observation that S stars and YSOs appear to orbit in a thin, well-defined disk around the black hole, suggesting some kind of regulatory mechanism within the systemThis behavior could also be related to gravitational interactions between the stars themselves, as well as with the gas and dust present in the region.
