Watching any cosmic object get devoured by a black hole is equal parts exciting and terrifying. Watching the same black hole recreate what it had only just destroyed? Add mysterious and confusing to the mix.
Two years ago, astronomers watched as a black hole situated in a galaxy known as 1ES 1927+654 slowly devoured an ultra hot disc of gas -- known as a black hole corona -- before gradually rebuilding another. Over the course of weeks, this facilitated a dimming of the black hole's luminosity by a factor of 10,000, followed by a subsequent brightening of over 20 times its original luminosity.
Scientists were puzzled as to what may have caused such an event.
A new study, published in the Astrophysics Journal Letters on Thursday, proposes a new hypothesis -- it may have been the work of a runaway star. According to the report, a possible explanation sees a rogue star ricocheting through the black hole, causing an avalanche effect of gravitation which sunk all neighboring matter into the black hole alongside it, including the corona.
This isn't the same kind of corona we're dealing with on earth right now -- but hey, if a black hole wants to take the coronavirus off our hands, that would be great. (Please don't blame me if this jinxes us and sees 2020 hit us with something cosmically catastrophic.)
A black hole corona is a bright feature comprised of X-rays, creating a flare that shoots outwards, allowing us to see its glow from millions of light years away. And it was the fluctuation of this glow that enabled scientists to posit an explanation.
"We just don't normally see variations like this in accreting black holes," said Claudio Ricci, lead author of the study and assistant professor at Diego Portales University in Santiago, Chile, in a release from NASA.
"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."
Given the dramatic variation in luminosity over time, it's still entirely possible the cause of the phenomenon was something else altogether, so further monitoring is required to bring more answers to the table.
"This dataset has a lot of puzzles in it," said Erin Kara, a coauthor of the new study and assistant professor of physics at MIT. "We think the star hypothesis is a good one, but I also think we're going to be analyzing this event for a long time."