Astronomers have uncovered a surprising behavior in black holes that has upended long-standing theories about how these cosmic giants interact with the stars they consume.Traditionally thought to go silent after a brief flare of activity, some black holes are now being observed emitting new bursts of energy years after devouring a star—”the equivalent of a cosmic burp,” as Yvette Cendes, a professor in the Department of Physics and Astronomy at the University of Oregon, wrote in Scientific American.These events, known as tidal disruption events (TDEs), occur when a star ventures too close to a black hole and is torn apart by its immense gravitational forces.Typically, about half the star’s matter is ejected outward while the remainder forms a glowing accretion disk—a structure made of gas, dust or other material that spirals inwards—around the black hole, briefly illuminating the cosmos in various wavelengths.For decades, scientists believed that once this brilliant flare faded, the process was over.However, recent radio telescope observations have revealed that a subset of these black holes re-ignite years after the initial event.”It’s a fascinating phenomena because researchers always thought that when a black hole tore apart and flared briefly, that was the end of the story,” Christopher Impey, an astronomer and faculty member at the University of Arizona, told Newsweek in an email.”But apparently some of the star material is activated within the accretion disk surrounding the black hole and it emits a burst of radio energy. Subsequent activity from a tidal disruption event was very unexpected.”‘More common’These delayed emissions suggest that material may linger in unstable orbits for much longer than previously believed, eventually triggering fresh outflows of energy.The re-ignitions aren’t isolated cases. Surveys of past TDEs have uncovered multiple instances where black holes that had seemingly gone quiet suddenly lit up again in radio wavelengths.The pattern suggests that late-stage activity may be more common than originally thought.Several TheoriesResearchers have proposed several theories to explain these delayed emissions.Some hypothesize that dense material in the accretion disk may periodically clash and create shocks that produce fresh bursts of radiation.Others suggest that changes in the magnetic environment around the black hole could be responsible for the renewed activity.Another possibility is that the accretion disk itself forms more slowly or evolves over time, creating conditions ripe for delayed emissions.”No information can escape a black hole,” Impey told Newsweek, “But it will tell us about how matter is processed and heated near the black hole.”What’s NextWith next-generation observatories like the Vera C. Rubin Observatory expected to detect thousands more TDEs annually, astronomers anticipate a flood of new data.Each new detection could help unravel the physics behind these mysterious black hole “burps”, offering fresh insights into some of the most extreme environments in the universe.”Black holes continue to surprise scientists, as well as hold onto some of their secrets tightly,” Impey said.