New study tracks the fate of stars living near the Milky Way’s central black hole

Despite their age, some stars orbiting the supermassive black hole at the center of the Milky Way galaxy look young at first glance. But unlike those who look rejuvenated after fresh collagen injections, there’s a darker reason why these stars look so young. They ate their neighbors. This is just one of the strange findings of a new study by Northwestern University. Astrophysicists used a new model to track the massive journey of 1,000 simulated stars as they orbited Sagittarius A* (Sgr A*), the supermassive black hole at the center of our galaxy . This region is so densely populated with stars that brutal stellar collisions occur frequently. By simulating the effects of such violent collisions, the new study shows that collision survivors either lose mass and become scraped-off, low-mass stars, or merge with other stars to become gigantic and tapered. We conclude that it can be a matter of appearance. “The region around the central black hole is densely packed with stars that are moving at very high speeds,” said Northwestern’s Sanaea C. Rose, who led the study. “It’s like walking through an incredibly crowded subway station during rush hour in New York City. Drive very close to others unless you collide with them. In the case of stars, these close collisions also result in gravitational interactions. We wanted to explore what these collisions and interactions mean for stellar populations and characterize their results. ” Rose will present this research at his April meeting of the American Physical Society (APS) in Sacramento, California. “Stellar Collisions at the Galactic Center” will be held on Thursday (4 April) as part of the “Particle Astrophysics and the Galactic Center” session.

per second instead of thousands. Because of their slow speed, these stars collide with each other, but they don’t have enough energy to escape. Rather, they merge and become increasingly large. In some cases, they may merge multiple times and reach a mass 10 times that of the Sun. “A few stars will be in the collision lottery,” Rose said. “Through collisions and mergers, these stars collect more hydrogen. They disguise themselves as rejuvenated, younger-looking stars, even though they are born from older people.” They are like zombie stars. They eat their neighbors. ” However, a youthful appearance is closely related to a shortened life expectancy. “They die quickly,” Rose said. “Massive stars are like giant gas-guzzling cars. They start out using a lot of hydrogen, but they burn it off very quickly.”

source: https://iopscience.iop.org/article/10.3847/2041-8213/ad251f