Researchers Discover: A Star "Survives" Encounter with a Black Hole

Recently, an international research team led by Tel Aviv University in Israel published a study in the US journal Astrophysical Journal Letters, reporting that they have observed for the first time a rare phenomenon: a star miraculously "survived" after encountering a supermassive black hole and experiencing a violent "tidal disruption event," and returned to the vicinity of the black hole again about two years later.

Researchers stated that almost every large galaxy center hosts a supermassive black hole with a mass millions to billions of times that of the Sun. Due to the extremely strong gravitational pull of black holes, even light cannot escape, making direct observation extremely difficult. Astronomers usually study black holes indirectly by observing the motion of nearby stars or the radiation generated by high-energy events. Approximately every 10,000 to 100,000 years, a star may wander close to a black hole and be torn apart by gravity, producing intense flares. This is known as a "tidal disruption event," providing scientists with a brief observational window to "illuminate" the black hole.

In 2022, researchers observed a flare named "AT 2022dbl," and about two years later, they captured an almost identical flare at the same location. This is the first confirmation that a star was not completely swallowed after being torn apart by a black hole, indicating that at least the first flare was the result of partial disruption of the star, with most of the star surviving and passing close to the black hole again, triggering another flare.

The researchers will next observe whether a third flare will be seen in early 2026. If it appears, it would prove that the second flare was also the result of partial disruption of the star, overturning the previous assumption among scientists that "a flare indicates complete disruption of the star." If no third flare occurs, the second flare may indicate complete disruption of the star.