There are certain words that are simply pleasing. They are a combination of sounds and mouth movements that just feel good. Arugula. I, for one, am fond of the word arugula even if I’m not entirely fond of eating arugula. Another such pleasing word is spaghettification. As its syllables are bounced back and forth along the speech palette, the word describes the end of stars, planets, asteroids, and maybe even people.
This word, spaghettification, describes how the differences in the pull of gravity between the near and far side of an object can cause that object to be torn apart – tidally disrupted if you want the science term – and then those disrupted pieces can get strung out as they fall toward the disrupting body, breaking up further as each piece is stretched and pulled apart until all that is left is the long tail of debris spiraling in toward its doom.
If you’re into cosmic death, spaghettification is a fascinating way to go. The human body, stretched under the pull of gravity into a string of atoms, would create a spiral that if laid straight would stretch 70 some odd light-years across the universe.
But mostly, spaghettification is just theoretical. Most of the time, the dusty and cluttered area around black holes obscures the flares and flashes of light that can be associated with objects being torn about.
But most of the time is not all of the time, and in an amazing case of luck and pre-planning, an international team of astronomers has been able to observe the slow demise of a star being tidally disrupted as it fell into a supermassive black hole.
Last September, a variety of all-sky surveys alerted astronomers to an increase in brightness in the center of the barred spiral 2MASX J04463790-1013349. Viewed from straight above this system, astronomers were able to catch an unimpeded view of what is believed to be a star being shredded.
Once the initial uptick in light was spotted, many of the world’s largest telescopes pointed at the system to see what was going on. The rise in brightness didn’t match a supernova, and it was located in the center of the galaxy rather than in a more traditional star-forming region or outer area where a supernova might normally be found. Instead, it matched the behavior of a star being spaghettified. According to the lead author of a new paper appearing in Monthly Notices of the Royal Astronomical Society (MNRAS): The idea of a black hole ‘sucking in’ a nearby star sounds like science fiction. But this is exactly what happens in a tidal disruption event.
According to the press release: To get a detailed look at just what happens when a star is devoured by a monstrous black hole, researchers pointed the European Southern Observatory’sVery Large Telescope (VLT) and New Technology Telescope (NTT) at a new flash of light that occurred close to a supermassive black hole last year. Follow-up observations occurred over a six-month period at multiple telescopes around the world, including the Center for Astrophysics | Harvard & Smithsonian’sMMT, located at the Fred Lawrence Whipple Observatory in Amado, Arizona.
This is the closest spaghettified star to so far be detected, and early detection by all-sky surveys allowed it to be studied before the star’s material could coalesce into dust and debris.
Co-author Kate Alexander explains: Because we caught it early, we could actually see the curtain of dust and debris being drawn up as the black hole launched a powerful outflow of material with velocities up to 10,000 km/s. This is a unique ‘peek behind the curtain’ that provided the first opportunity to pinpoint the origin of the obscuring material and follow in real-time how it engulfs the black hole.
The observations themselves aren’t entirely satisfying; the system got brighter and fainter. The coolest science will come later when detailed models explaining the star’s final days can be published. This is our reminder that observers catch only hints of what is happening, and it is through computer models that match those observations that we tease out the details.
“An Outflow Powers the Optical Rise of the Nearby, Fast-Evolving Tidal Disruption Event AT 2019qiz,” M. Nicholl et al., 2020 Oct. 12, Monthly Notices of the Royal Astronomical Society (preprint on arxiv.org)