A Deep Gravitational Sinkhole Twists an Unlucky Star Into Donut Shape

A Deep Gravitational Sinkhole Twists an Unlucky Star Into Donut Shape ...

During a 'tidal disruption event,' a star is depicted sucked into a supermassive black hole. Credit: ESO/M. Kornmesser

Black holes have a powerful gravitational pull that they even swallow light. This makes them hungry monsters lurking in the eternal darkness. It's no wonder astronauts have yet to reach the Moon, but whole stars can be at danger if they end up at the wrong spot at the wrong time.

When Hubble astronomers were alerted to a flash of high-energy radiation from a 300 million light-years away, they were trained on the danger before the collision was over. Instead, they examined the starlight that accumulated during the collision.

The star's outer gasses are pushed into the black hole's gravitational field, and the stellar remnants will eventually fall into the black hole, releasing a tremendous amount of light and high-energy radiation.

Black holes are not hunters, but gatherers. They wait until a hapless star emerges. When the star is close enough, the black hole's gravitational grasp rips it apart and sloppily devours its gasses, releasing intense radiation.

The final moments of a star as it gets eaten by a black hole have been recorded by NASA's Hubble Space Telescope.

The term "tidal disruption" refers to a particular type of incident. There is a delicate, rawness to the encounter with a black hole. In other words, black holes are messy eaters. Astronomers are using Hubble to discover what happens when a wayward star plunges into the gravitational abyss.

Because the tidal event AT2022dsb is only 300 million light-years away at the core of the galaxy ESO 583-G004, astronomers studied the light from the shredded star, which included hydrogen, carbon, and other elements. The spectroscopy provides further evidence of the black hole homicide.

The Hubble Space Telescope's astronomers have recorded a star's final moments in detail as it is swallowed up by a black hole. Credit: NASA's Goddard Space Flight Center, Lead Producer: Paul Morris

Several telescopes have detected more black hole tidal disruption events on March 1, 2021, which took place in another galaxy. Data was collected using X-ray light from an extremely hot corona around the star that had already been torn apart.

"We're extremely disappointed because there's a lot of information that you can get from the ultraviolet spectra," said Emily Engelthaler of the Harvard & Smithsonian (CfA) in Cambridge, Massachusetts. "The tidal event can reveal a lot about a black hole." Changes in the doomed star's condition are on the order of days or months.

The stellar shredding in any given galaxy with a quiescent supermassive black hole at the center is thought to be only once per 100,000 years.

The All-Sky Automated Survey for Supernovae (ASAS-SN or "Assassin") first detected this AT2022dsb stellar snacking event on March 1, 2022. This energetic collision was close enough to Earth and bright enough for Hubble astronomers to perform ultraviolet spectroscopy for a longer period of time than usual.

'Typically, these events are difficult to observe. You get maybe a few observations at the beginning of the disruption when it's really bright.' said Peter Maksym of the CfA. "We saw this early enough that we could observe it during these very intense black hole accretion phases."

The Hubble spectroscopic data are thought to originate from a very bright, hot, donut-shaped area of gas that once contained the star. This area, called a torus, is the size of the solar system and is curving around a black hole in the middle.

“We’re looking around the edge of a donut. A stellar wind from the black hole is sweeping over the surface at a speed of 20 million miles per hour,” said Maksym. “You shred the star and then it’s got this material that’s making its way into the black hole.” This is an exciting place for scientists to be: right at the interface of the known and the unknown.

At the 241st American Astronomical Society meeting in Seattle, Washington, the results were presented during a press conference on January 12, 2022.

The Hubble Space Telescope is a project of NASA and ESA. The NASA's Goddard Space Flight Center in Greenbelt, Maryland, operates the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, provides NASA's research on Hubble and Webb.

You may also like: