Researchers studying a supermassive black hole located in galaxy 1ES 1927+654, located millions of light-years away, have detected a peculiar phenomenon in that celestial body's corona as it suddenly “snuffed out” before "gradually returning to brightness", Science Alert reports.
According to the media outlet, the scientists witnessed the black hole's corona dimming and brightening over the course of 40 days, while they apparently expected the kind of changes they observed to occur over a much longer period of time.
"We expect that luminosity changes this big should vary on timescales of many thousands to millions of years," said Erin Kara, physicist from the Massachusetts Institute of Technology. "But in this object, we saw it change by [a factor of] 10,000 over a year, and it even changed by a factor of 100 in eight hours, which is just totally unheard of and really mind-boggling."
The astronomers first noticed that something was amiss in 1ES 1927+654 when the All-Sky Automated Survey for Super-Novae (ASASSN) detected an "incredibly bright flare" from the galaxy.
Subsequent observations revealed that 160 days after said flare, the galaxy's nucleus started to dim, getting "totally snuffed out" in 40 days; yet, after 300 days of the initial flare, the nucleus was "shining almost 20 times more brightly than it had been prior to the initial event", the media outlet notes.
"We just don't normally see variations like this in accreting black holes," said astrophysicist Claudio Ricci of Diego Portales University in Chile, lead author of the study. "It was so strange that at first we thought maybe there was something wrong with the data. When we saw it was real, it was very exciting. But we also had no idea what we were dealing with; no one we talked to had seen anything like this."