Astronomers call it “spaghettification”: what happens when you venture too close to a black hole and fall in. Tidal forces stretch you and break you like a noodle, then your shreds circle the black hole until they collide and knock one another in.
On the upside, the energy released by your long fall and the crashing together of what used to be your atoms might produce a flash that can be seen across the universe.
In a case recently reported, it was merely an anonymous star in a faraway galaxy that met its doom. Thanks to luck and ever-increasing vigilance of the heavens, the whole world was watching.
“Indeed, it was quite a feast,” said Matt Nicholl, an astrophysicist at the University of Birmingham in England.
He led a team of astronomers that described this stellar apocalypse in the Monthly Notices of the Royal Astronomical Society.
“This black hole was a messy eater,” added Kate Alexander of Northwestern University and a member of Nicholl’s team.
In the end, she said, only about half the star was consumed by the black hole. The rest was blown outward into space at a breakneck speed.
Black holes are gravitational potholes in space-time predicted by general relativity, Albert Einstein’s theory of gravity. They are so deep and dense that nothing, not even light, can escape them. Our Milky Way galaxy, and presumably most galaxies, are littered with black holes produced when massive stars died and collapsed in on themselves.
“We know that most galaxies have supermassive black holes at their centers,” Alexander wrote in an e-mail. “But we still don’t understand exactly how these black holes grew to be as big as they are, or how they shape their host galaxies.”
Studying stellar disruptions, she said, could help in understanding how these black holes eat, grow and interact with their environment.
The black hole in the Eridanus galaxy weighs about 1 million solar masses. As reconstructed by Nicholl and his team, a star about the size and mass of our own sun wandered into the center of the galaxy and came too close — about 100 million miles — to the black hole.
That’s roughly the distance from Earth to the sun. At that point, the gravitational pull from the black hole exceeded the gravitational pull from the star’s core, and the star was “spaghettified” into a long stream around the hole. Eventually the stream wrapped around the black hole and collided with itself, “which is when the black hole began sucking it in,” Nicholl said. “If you were to picture the sun being stretched into a thin stream and rushing toward us, that’s what the black hole saw.”