- In space, no one can hear you toot.
Space is a scary place in general, but perhaps the most terrifying thing out there is black holes. You can barely observe them until you’re caught in their enormous gravitational pull and compressed into the infinitely dense singularity at their center.
Their gravity is so strong that nothing can escape them — not even light. Nothing ever leaves a black hole.
Or so we thought. As it turns out, some things may get out of a black hole.
You see, a black hole will devour anything that comes near it. But just like you would if you ate tons of all kinds of junk, black holes may eventually get… Gassy.
Scientists had never bothered to keep an eye on black holes after they sucked in a star — nothing should come out of it, after all. But once they did, they noticed that black holes could spew back some of the material they ate after multiple years.
The researchers who noticed the phenomenon referred to it as “burping.” We brilliant minds at Oddee have, however, determined it more scientifically appropriate to refer to the process as “farting.”
Why? Because we’re children like that.
That’s-a Spicy Star Ball
Before we can get into the cosmic toots, we need to understand what and how a black hole eats. After all, you should always think back to what you ate if you get an upset stomach.
The thing about black holes is, they like pasta.
Imagine an innocent little star. Let’s call him Twinkle. Twinkle is floating out in space, minding his own star business.
Suddenly, Twinkle feels something tugging at him. The pull gets stronger and stronger until Twinkle realizes it can’t continue in its orbit.
Oopsie-poopsie! Twinkle has been caught in a tidal disruption event (TDE) — and he’s about to be ripped to shreds.
Once a star like Twinkle ventures too close to a black hole, the celestial beast’s ridiculous gravity exerts such strong tidal forces on the star that it begins to stretch toward the hole while compressing in a parallel direction. It looks much like stretching out a piece of dough into a noodle.
That’s why the process is called spaghettification.
As the black hole slurps up the noodle that once was Twinkle, it unravels his structure and breaks it into its basic components. This process results in a strong burst of electromagnetic radiation that astronomers’ sensors can detect.
The black hole swallows some of the material immediately, while the rest forms a thin disc-like cloud around the hole, called an accretion disc. As this unstable disc swirls around the black hole, it slowly sucks all of it up until nothing is left.
Delayed Incontinence
It’s at this point — a few months after the TDE — that astronomers generally stopped observing black holes. They just didn’t see much point to it, considering the holes’ inescapable nature.
One group of scientists, however, decided to keep an eye on the scene of interstellar gluttony. Doing so, they noticed that black holes have terrible table manners.
Roughly half of the observed black holes began farting consumed matter back into space several years after the TDE. Researchers can see that because the black holes suddenly begin emitting electromagnetic waves again.
“If you look years later, a very, very large fraction of these black holes that don’t have radio emission at these early times will actually suddenly ‘turn on’ in radio waves,” Yvette Cendes, the new research’s lead author, told LiveScience.
“I call it a ‘burp’ because we’re having some sort of delay where this material is not coming out of the accretion disk until much later than people were anticipating,” she added.
She calls it a burp, we say it’s a fart. To-may-to, to-mah-toe.
The Great Question
The farts begin on average two to six years after the TDE. But why do they happen?
Well, that’s the question. Neither Cendes nor anybody else knows what makes the holes spew gas (and other stellar matter).
Finding out the cause is particularly hard because our current black hole simulations end too soon. The simulations generally terminate a few weeks after the TDE, so there’s no way they could model the newly observed emission.
One thing is certain, though. The matter isn’t coming from within the black holes. Once you’re there, you’re not coming back out — that hasn’t changed.
Instead, the electromagnetic radiation may originate from the accretion disc. However, the researchers aren’t certain yet.
“Black holes are very extreme gravitational environments even before you pass that event horizon, and that’s what’s really driving this. We don’t fully understand if the material observed in radio waves is coming from the accretion disk or if it is being stored somewhere closer to the black hole,” said Cendes.
“Black holes are definitely messy eaters, though,” she concluded.
We may not be scientists, but we do have a competing theory. We propose that it simply takes some time for the black holes to digest the star before they notice they ate something they shouldn’t have.
And then there’s no stopping the farts anymore.