While NGC 7392 was at the center of the galaxy, a supermassive black hole tore apart a star in a nearby galaxy. A flash of light from a black hole’s dinner finally reached Earth in 2014, and astronomers discovered it in their data. This newly discovered flare from the center of NGC 7392 is the closest example of a tidal decay event (TDE) in which a star is torn apart by the gravity of a black hole. Findings published Astrophysical Journal Letters.

The hungry black hole was detected about 137 million light-years from Earth, or about 35 million times further from Proxima Centauri, the closest star to the Sun. As exaggerated as it may sound, astronomers have observed only about 100 such events so far, four times closer to the previous holder of the “closest TDE to Earth” designation. The scientists detected TDE in infrared radiation, which has different wavelengths than most conventional TDE detections that typically occur in X-rays, ultraviolet, and optical light.

“To find this near a TDE statistically means there must be a large population of these events that conventional methods have not seen,” lead author Christos Panagiotou, an astronomer at MIT, said in a statement. “If we want to get a complete picture of black holes and their galaxies, we should try to find them in the infrared.”

After first detecting a TDE with observations from the NEOWISE space telescope, Panagiotou and colleagues looked to data from many other observatories and space telescopes to learn more about supermassive black hole NGC 7392. They wanted to solve the mystery of why this TDE only appeared. in the infrared range and not at more energetic wavelengths like others of this kind.

Previously detected TDEs mostly occurred in green galaxies that did not form as many stars as the more active blue galaxies, but did not burn out completely during star formation, such as red galaxies. But NGC 7392 is a blue galaxy that is producing many new stars and producing a lot of dust in the process. This dust can obscure the center of the galaxy that hosts the supermassive black hole in optical and ultraviolet light. But infrared light allows astronomers to pass through this dust and see what’s going on. This discovery indicates that astronomers should also look for TDEs in the infrared.

“Using infrared surveys to detect dusty echoes of obscured TDEs has already shown us that there is a TDE population that we cannot see in dusty star-forming galaxies,” said Suvi Ghezari, an astronomer at the Space Telescope Science Institute. included in the study. Scientists looking for TDEs also in the infrared may be one step closer to understanding how black holes eat stars.