Astronomers call it “spaghettization,” and it’s not a very good idea: it’s what happens when you venture too close to a black hole and fall. Tidal forces stretch you and smash you like noodles, then your pieces circle a black hole as they collide and knock each other.
On top of that, the energy released by your prolonged fall and the shattering of what used to be your atoms can cause a flash – a cosmic funeral pyre, if you will – that can be seen all over the universe.
In the case reported last week, it was just an anonymous star in a distant galaxy that met its doom. Thanks to luck and the ever-increasing vigilance of the heavens, the whole world watched the star set.
“Indeed, it was a real holiday,” said Matt Nicholl, an astrophysicist at the University of Birmingham in England, in an email. He led a group of astronomers who described the stellar apocalypse in a monthly report from the Royal Astronomical Society on Monday.
“This black hole was a messy eater,” added Kate Alexander of Northwestern University and a member of Dr. Nicole’s team in an email. In the end, she said, the black hole absorbed only about half of the star. The rest of its decomposed material was carried into space at an insane speed that was several percent faster than the speed of light.
The excitement began on September 19, 2019, when the Zwicky transition installation, the telescope on Mount Palomar in California and other celestial observation networks discovered a flash in the center of the galaxy, located 215 million light years from Earth in the constellation Eridan.
The torch had signs of a tidal event – a technical name when a black hole tears a star to shreds and eats it.
Astronomers rushed to their ground and space telescopes to track AT2019qiz, as the flash was called. (“AT” means “astronomical transition process.”)
Over the next few weeks, the outbreak intensified rapidly. At its peak, it exploded about a billion times more energy than our sun. Over the next five months, the outbreak slowly subsided.
The result is a unique and multidimensional view – based on radio radiation, X-rays and gamma rays, as well as old-fashioned observations of visible light – on the complexity of death from a black hole.
Black holes are gravitational holes in space-time, provided by the general theory of relativity, the theory of gravity by Albert Einstein. They are so deep and dense that nothing, not even light, can escape them. Our Milky Way galaxy, and perhaps most galaxies, is littered with black holes that form when massive stars perish and collapse on themselves. In addition, it seems that each galaxy is based on an oversized version of one of these monsters millions or billions of times more massive than the sun.
“We know that most galaxies have a supermassive black hole in their centers,” Dr. Alexander wrote in an email. “But we still don’t understand exactly how these black holes became as big as they are, or how they form their host galaxies.” Studying stellar faults, she said, could help understand how these black holes feed, grow and interact with the environment.
A black hole in the galaxy Eridan weighs about a million solar masses. As reconstructed by Dr. Nicole and his team, a star the size and mass of our own sun got lost in the center of the galaxy and came too close – about 100 million miles – to a black hole.
This is approximately the distance from the Earth to the Sun. At that point, the gravitational pull of the black hole exceeded the gravitational pull of the star’s core, and the star was “spaghettized” by a long stream around the hole. Eventually, the stream enveloped the black hole and collided with itself, “that’s when the black hole began to suck it in,” Dr. Nicholl said.
He added: “If you could imagine the sun stretching in a thin stream and rushing towards us, that’s what the black hole saw.”
Recently, astronomers have documented other similar black hole breakdowns, but such events rarely occur so close to our own galaxy, and their internal dynamics are often overshadowed by the dust and gas that cause a fatal collision. In this case, astronomers were able to see behind that curtain and notice that it is made of pieces of a crushed star.
“Because we caught it early, we could see the curtain of dust and debris rise as the black hole began a powerful outflow of material,” said Dr. Alexander.
Most of the light they saw came from this material, which was blown into space at about 6,000 miles per second. Spectral studies have shown that the material flowing out of the black hole is identical to the one that fell – evidence that it is crumbs from a clumsily eaten star.
The AT1910qiz torch can serve as a “rosette stone” for understanding other events that crush stars, Dr. Alexander said. AT2019qiz was special, she added, as astronomers began observing it very early, right after the star was broken, and collected so much data from different types of telescopes.
New telescopes, such as the Vera Rubin Observatory and the European Extremely Large Telescope under construction in Chile, should attract even more of these space Instagrams.