Astronomers discover a black hole’s favorite snack: “The star seems to live to die another day”
Astronomers have managed to predict the meals of a colossal black hole after watching it devour a nearby star in pieces, they announced earlier this week, taking a step forward in understanding the elusive eating behavior this cosmic emptiness.
The data underlying the forecasts were transmitted in 2018, when an automated ground-based survey indicated an increase in brightness in a galaxy about 860 million Light years from Earth. The flare — which could be compared to the flipping on of a cosmic light switch billions of times brighter than our sun — suggested that a star was being ripped apart and devoured by a supermassive black hole lurking at the center of a distant galaxy that is about 50 million times more massive than our sun.
The star’s decimated material heated up as it approached the black hole, emitting X-rays and ultraviolet radiation strong enough to be detected by space telescopes. These signals faded just over a year later, suggesting that the black hole had completely swallowed the starHowever, two years later, the signals appeared to increase again, showing that the star’s core had indeed survived the first flyby, while its outer layers were destroyed.
Based on telescope data about the star and its orbit, astronomers used a model to predict the black hole’s penultimate meal before August 2023. The results were confirmed by follow-up observations with the Chandra X-ray telescope, which recorded the predicted decline in the system’s bright emissions.
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“At first we thought it was a very common case of a black hole tearing a star apart,” said Thomas Wevers of the Space Telescope Science Institute in Baltimore, who Observations 2023said in a opinion. “Instead, the star seems to live to die another day.”
“The black hole essentially wiped its mouth and pushed itself away from the table,” added Dheeraj Pasham, a scientist at the Massachusetts Institute of Technology who led the recent study, in the same statement.
The ill-fated star also had a companion star that was hurled into space at a speed of about 1,000 kilometers per second, study co-author Muryel Guolo of Johns Hopkins University in Baltimore explained in the statement. “The doomed star was forced to change its companions drastically – from another star to a giant black hole,” Guolo said. “Its stellar partner escaped, but it did not.”
The star that remained bound to the black hole was eventually devoured in small portions at a time, which is different from the traditional “one-and-done” meal of a black hole. According to the researchers, this offers a new opportunity to investigate the physics of black holes’ behaviour.
“We expect this model will be an important tool for scientists in identifying these discoveries,” said study co-author Eric Coughlin, a professor of physics at Syracuse University in New York, in a university speech. Press release.
From the most recent data Chandra and Swift have collected, researchers predict that the shredded star comes closest to the black hole every 3.5 years. Its orbit suggests that the black hole’s third meal — that is, if there’s anything left of the star — would begin between May and August of next year. If that feast does indeed happen, it will last nearly two years, Coughlin said.
“This will probably be more of a snack than a full meal, because the second meal was smaller than the first and the star is slowly being worn away.”
A study These results were published on Wednesday (August 14) in The Astrophysical Journal Letters.
