- Scientists have created new computer simulations to study what happens during a supernova.
- Their models show that sometimes when stars die, they form a black hole that goes screaming into space.
- These black holes get kicked into space, moving as fast as 1,000 kilometers per second.
Scientists studying how supernovas explode may have discovered a new process for how certain black holes form.
Turns out, some baby black holes hit the ground running at colossal speeds just moments after they take shape.
Typically, black holes form from the core of a supermassive star after it explodes in a brilliant burst of light, called a supernova. The core accretes, or collects, left-over gas from the star's guts, until it grows to be so dense, that it forms a black hole.
However, the speed, shape, and size of the initial explosion varies widely depending on the mass and density of the parent star before it explodes.
Moreover, those factors play a key role in what happens to the star's core and how it may form a black hole, according to a new study posted on the preprint server ArXiv.
For example, when a parent star is of relatively low mass and very compact, computer simulations suggest that it will explode symmetrically, forming a near-perfect sphere.
But when the star is very massive and less compact, the supernova is more asymmetrical and the explosion typically lasts longer, according to the new study.
"So you're exploding in one direction more than other directions, and in those other directions, it's very possible that you have continued significant accretion," that could lead to a black hole, Adam Burrows, the lead author of the paper and a professor of astrophysical sciences at Princeton University, told Business Insider.
Something else happens from supernova explosions. The stellar remnant gets a kick into the universe, and when the explosion is asymmetrical, that kick can be pretty intense, Burrows said.
The kick is exactly what it sounds like. The object — a black hole in this case — is sent flying off into space, sometimes at colossal speeds of up to 1,000 kilometers per second, or about 2.2 million mph.
It's like the recoil from a gun after firing a bullet, Vijay Varma, an assistant professor in of mathematics at the University of Massachusetts Dartmouth who was not involved in the research, told Business Insider.
So, for a brief while after birth, these black holes may be moving throughout space, sometimes as fast as 1,000 kilometers per second, the paper theorizes. But this movement is probably temporary, and somewhat rare, Burrows said.
"They're not zooming around, and circling, and causing all sorts of damage as they stay inside the galaxy," Burrows said.
Building a universe inside a computer
The new study includes 20, 3-D simulations of a supernova explosion.
"This is the largest set of long-term (many seconds after bounce) 3D state-of-the-art core-collapse simulations ever created," the researchers reported in the paper.
Previous simulations of this type of scenario have been too short to arrive at conclusions about how stellar cores are then shot out into the universe, Burrows said.
That's because these computer simulations take tens of millions of zones, and each zone contains information about the windspeed, temperature, barometric pressure, and other features of this theoretical environment, like mapping weather.
Think of all the complexities of building a universe inside a computer. Not many academic programs have access to super computers that are able to build these simulations, Burrows said.
Though Varma doesn't study supernova death, he said that theoretical work like this has implications for many other fields of astrophysical research.
"All of this theory is very important. And as we connect them to observations, we can try to trace the evolution of the black holes back in time," Varma said.
If the black holes are moving
If you hear blazing-fast black holes and start to panic, don't. Burrows said it is incredibly unlikely that these blackholes would travel into our solar system.
Space is so vast, Varma added, that you'd be better off betting on the lottery than waiting for a black hole to come visit our solar system. "It's astronomically unlikely that anything like that will happen," he said.
In the unlikely scenario that a black hole or a neutron was headed towards us, Burrows said, "then it would be a bad day."
The fact that our planet and the rest of the solar system have survived for the last 4.5 billion years should be reassurance enough that a black hole won't come screaming through our neighborhood anytime soon, if ever.
The study has been accepted for publication in the peer-reviewed Astrophysical Journal.