Astronomers recently observed a rare cosmic event where a supermassive black hole, located approximately 408 million light-years away, consumed one star from a binary system while the other narrowly escaped. This unusual phenomenon, known as a double-flash tidal disruption event (TDE), occurred in the galaxy WISEA J122045.05+493304.7. These powerful events, visible from billions of light-years away, typically involve a single flare, but the designated event ASASSN-22ci is notable for producing two flares, sparking interest in its origins and implications for black hole research.
A Unique Event Observed
According to a study published in the pre-print journal arXiv, ASASSN-22ci was first detected in February 2022, appearing as a typical TDE. However, a second flare was observed 720 days later, making it one of the few documented instances of repeated TDEs.
Researchers theorize this might have resulted from a process called Hills capture, where a supermassive black hole disrupts a binary star system. In such cases, one star is ejected at high velocity, while the other remains bound in an elongated orbit around the black hole, undergoing repeated tidal disruptions.
Investigating the Black Hole's Activity
Data from ultraviolet and X-ray observations revealed the black hole responsible for ASASSN-22ci has an estimated mass of about three million times that of the sun. While the star involved in these flares likely has a mass similar to the Sun, it remains uncertain if it had a companion that escaped. Scientists believe the similarity between the two flares indicates that the same star may have been disrupted twice during its orbit.
Looking Ahead to 2026
Researchers predict a third flare could occur in early 2026 if the star survives another close encounter with the black hole. This anticipated event would provide astronomers with a rare opportunity to observe and study the earliest phases of a TDE in unprecedented detail, shedding light on the mechanics of black hole interactions with stars.