Astronomers theorize that the enormous black hole situated at the core of the Milky Way might have interacted with another black hole in the last 10 million years. Positioned about 26,000 light-years distant, Sagittarius A* is a supermassive black hole roughly 4 million times heavier than the sun. It is believed that Sgr A* assimilated a smaller black hole, which could account for the peculiar movements of a cluster of stars close to the galaxy’s nucleus. These S-stars exhibit erratic trajectories, contrasting with other nearby stars that follow more consistent paths. Their unpredictable orbits are intriguing, particularly as they are relatively young, indicating a swift reason for their dynamics.

Scientists employed computer models to recreate historical cosmic occurrences. They discovered that if a smaller black hole amalgamated with Sgr A*, it might have triggered a recoil effect, disturbing the orbits of adjacent stars without relocating the black hole from the core. The results are documented in The Astrophysical Journal Letters.

Once merely a concept, black holes are now widely recognized in the scientific community. They are even being captured in images by a network of radio telescopes on Earth. Unlike planets or stars, black holes possess an “event horizon,” a boundary past which nothing can escape their gravitational pull. Stellar black holes arise from the collapse of massive stars, but the origins of supermassive black holes remain uncertain. Astrophysicists contend that these massive entities are present at the cores of most galaxies, with NASA’s Hubble Space Telescope bolstering the idea that they emerge in starburst galaxies.

The Milky Way, aged over 13 billion years, has presumably absorbed smaller galaxies, some of which harbored black holes. If one of these black holes fused with Sgr A*, it might have generated gravitational waves, slightly shifting Sgr A*. Over an extended period, this could have modified the orbits of nearby stars, leading to the formation of the S-star cluster. Researchers examined this theory through simulations, which indicated that a smaller black hole fusing with Sgr A* could create star orbits akin to those of the S-stars. Although the model requires further refinement, it provides valuable perspectives on the evolution of the Milky Way’s central black hole and the development of galaxies.