The star that twice challenged a black hole

The first case of a star that survived a close encounter with a supermassive black hole and then returned to challenge it a second time has been discovered: its feat is evidenced by two flares observed in the same point in deep space almost two years apart , as reported in The Astrophysical Journal Letters by an international team of astronomers led by Tel Aviv University.

At the heart of every large galaxy lurks a supermassive black hole with a mass millions or billions of times that of the Sun. On average, once every 10,000 to 100,000 years, a star gets too close and is torn apart: some is swallowed by the black hole, while the rest is hurled outward. When matter falls into a black hole , it does so in a circular motion , like water going down a bathtub drain. Around black holes, however, the rotating matter approaches the speed of light , heats up, and radiates intensely, 'illuminating' the black hole for several weeks or months.

In 2022, astronomers observed a similar event, called AT 2022dbl, and 700 days later they saw another nearly identical one coming from the same location. This repetition suggests that at least the first flare was the result of the partial destruction of the star , with much of it surviving and returning for a further (nearly identical) pass . These flares would therefore indicate 'snacks' from the black hole, rather than actual 'meals'.

"The question now is whether we will see a third flare in another two years, in early 2026," says Iair Arcavi, director of the WISE Observatory in Mitzpe Ramon, Israel. " If we observe a third flare ," Arcavi continues, "it will mean that the second one also caused the partial destruction of the star . So perhaps all these flares, which for a decade we have been trying to interpret as complete stellar destructions, might not be what we thought."