When black holes slurp up stars, they make a mess on a galactic scale. Now, astronomers have gotten the best look yet at a black hole swallowing a star, called a tidal disruption event. The details were published on October 12 in the Monthly Notices of the Royal Astronomical Society.
In 2019, astronomers at the Zwicky Transient Facility in California saw a flare pop up in a galaxy in the constellation Eridanus, Dennis Overbye reports for the New York Times. A star near the size of our sun had fallen too close to the galaxy’s central black hole, and the intense gravity had begun stretching, squishing and shredding the star into stellar noodles. By the end of the event, months later, the black hole slurped up half of the star’s mass, and the rest was shot out into space.
At only about 215 million light-years away, this light lunch provided an unprecedented look into the stages of a star’s spaghettification.
“We were able to capture this event early because it is the nearest tidal disruption event seen to date,” astronomer Edo Berger of the Harvard & Smithsonian Center for Astrophysics tells Smithsonian in an email. “Since the more nearby an object is, the brighter it will appear to be, this allows us to discover such an object well before it reaches its peak brightness.”
Breakthrough research on black holes won three physicists the Nobel Prize this year. The supermassive cosmic phenomena are deep, dark pits in the fabric of space-time first described by Albert Einstein, where the gravity is so strong that at a certain point, nothing can escape its pull.
“If you get close enough to a black hole that you’re within this region called the ‘event horizon’ and you shine a flashlight away from the center of the black hole the light will go towards the center of the black hole,” astrophysicist Katie Mack told Inverse’s Danny Paez in 2018. “…That’s the point of no return because it’s physically impossible to move away from the center of the black hole, all directions are towards [its] center.”
The black hole in the new study is about a million times more massive than the star it consumed, according to a statement. Once the star was within 100 million miles—about the same distance as Earth to our sun—of the black hole, it was doomed. The star gets stretched out into a long stream around the black hole, and when the ends collide, some debris is thrown out into space while the black hole begins to pull the spaghettified star in.
“If you were to picture the sun being stretched into a thin stream and rushing toward us, that’s what the black hole saw.” University of Birmingham astrophysicist Matt Nicholl tells the New York Times.
Because astronomers caught a glimpse of the event early on, they organized a team across the world’s largest and best telescopes and watched the black hole consume the star over the course of six months.
“It seems to have paid off because we really got a great look at this thing,” Nicholl tells Paola Rosa-Aquino at Popular Science. The flare peaked in brightness after about one month, and faded five months later.
“These faster ones are harder to find, so it suggests that there might be a lot of these short-lived flares that have escaped our attention until now,” Nicholl adds to Popular Science.
Astronomers captured the event in x-ray and gamma ray, radio emissions, and visible light images. They found that most of the light came from the wall of dust and debris from the star that surrounded the black hole. The spaghettified star’s collision launched material into space at 6,000 miles per second, per the New York Times. At that speed, something could travel from Earth to the Moon in about 40 seconds.
As astronomers gain access to new, advanced telescopes like the Vera Rubin Observatory, researchers will be scanning the skies with more sensitive equipment. That may enable them to capture more of these star-shredding events early, Berger says.
“We know that most galaxies have supermassive black hole at their centers,” Northwestern University astronomer Kate Alexander wrote in an email to the New York Times. “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.”