In the heart of the Milky Way, deep within the universe, lies a massive black hole—Sgr A*. It possesses a mass over 4 million times that of the sun, its powerful gravity drawing numerous stars to orbit around it at high speeds. These celestial bodies are like insects trapped in a spider's web, constantly at risk of becoming the black hole's next meal. Unfortunately, this means that the space around the black hole is incredibly crowded—in contrast, the sun's nearest star is 4 light-years away, yet within the same distance from Sgr A*, over a million stars are clustered.

In theory, such a harsh environment is not conducive to the birth of new stars. The destructive nature of a black hole tears apart the surrounding material, whereas star formation requires a calm and gentle space for the fragile gas and dust to collapse under its own gravity. The strong tidal forces near a black hole are an immense challenge to overcome, making it seem nearly impossible for gas to coalesce into stars.

However, it appears that the cradle of the universe is not only filled with ancient old stars but also with young new stars that sparkle and shine. Astronomers are puzzled by the "youthful paradox" near this area, meaning that the existence of young stars, which should not be present near a black hole, has been observed. Some research suggests that these young stars may have been born in regions far from the black hole and were later relocated near it due to some accidental events. Other studies support the idea that perhaps the conditions in certain specific areas around the black hole are surprisingly favorable for the formation of new stars.

There is also an unsettling hypothesis regarding these abnormally young stars: they might not actually be young. It seems these stars may have "devoured" surrounding stars to exhibit signs of agelessness, as if they have applied an eternal preservative to themselves.

When exploring the tense "neighborly relations" among stars, we need to understand their dynamics in a narrow and crowded space. The enormous gravitational pull of the black hole causes stars to "dance" at incredible speeds, reaching hundreds or even thousands of kilometers per second. In such a dense interstellar environment, interaction between stars is inevitable.

"Imagine yourself swiftly navigating through rush-hour crowds in the subway; even though you don't always bump into people, you still inevitably come into contact with others." Rose analogizes, "Stars may only have 'brushed past' each other, but it's enough for their gravity to affect each other."

Rose and her team used the latest models to simulate the trajectories of a thousand stars orbiting the Sgr A* black hole. The study shows that within 0.1 arcseconds of the black hole, any star with a mass similar to that of the sun is likely to collide at least once in its lifetime. When stars approach the black hole at 0.01 arcseconds, they move at higher speeds, increasing the frequency and intensity of collisions between them.

Some stars may be directly destroyed in such collisions. However, a more common scenario is that they merely graze each other, like a "vigorous high-five," causing the stars to eject some material and lose their outer layers. These frictions and clashes have gathered a group of peculiar, low-mass stars around the black hole, striped of their outer layers.

On the other hand, a different scene is presented in regions farther away from the black hole. Here, stars move at a slower velocity, approximately several hundred kilometers per second. At such speeds, stars that collide or come into contact may be captured by the gravity of the other and eventually "devoured." The result is that two stars collide and combine, forming a more massive celestial body.

In this process, smaller stars (for example, ones the size of the sun) can increase their mass through multiple collisions, sometimes reaching ten times the mass of the sun or more. Those celestial bodies that have "devoured" other stars not only absorb a significant amount of hydrogen, which is an important fuel for stellar combustion, but as a result also become brighter and appear younger on the surface. However, not all rejuvenation means a prolonged lifespan. For stars that grow larger through merging, the faster rate of hydrogen burning might actually lead to a comparatively shorter lifespan.

Ross concluded, "Massive stars are like fuel-guzzling giant cars that, despite having a large amount of fuel, consume this fuel at astounding rates." Related research was recently published in The Astrophysical Journal Letters.

Ross and his colleagues' research provides scientific support for one hypothesis of the "youth paradox" and also serves as an important reference for understanding the historical evolution of our Milky Way galaxy. Ross states, "The vicinity of the supermassive black hole is indeed a special environment." He continues to explain, "In such a densely populated region, the star clusters influenced by the supermassive black hole are completely different from any cosmic bodies we have observed in the neighboring regions of the solar system." Ross believes that if we can thoroughly study these star clusters, we might gain a deeper understanding of the formation and evolution of the center of the Milky Way. He summarizes, "At the very least, these studies provide an interesting and worthwhile point of comparison for the cosmic region we inhabit."