The supermassive black hole at the center of the Milky Way galaxy suddenly flashed twice as brightly as scientists had ever seen in 20 years of observation.
Nobody knows what caused the flash, but two objects that passed near the black hole in 2014 and 2018 could be the culprits.
The flash was so bright that researchers want to update models of how the black hole fluctuates over time.
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The supermassive black hole at the center of the Milky Way is normally quiet, but in May it surprised astronomers with an unprecedented explosion of infrared light.
The closest supermassive black hole to Earth, called Sagittarius A* or Sgr A*, suddenly got 75 times brighter than normal along the near-infrared region of the light spectrum for two hours on May 13, a team of scientists as found.
According to a new paper they published on August 5 in arXiv, a Cornell University repository for scientific papers that are not yet peer-reviewed, this was the brightest flash scientists had seen in 20 years of observing the black hole — and twice as bright as any previously recorded.
“The black hole was so bright I at first mistook it for the star S0-2, because I had never seen Sgr A* that bright,” Tuan Do, an astronomer and lead author of the paper describing the event, told ScienceAlert. “I knew almost right away there was probably something interesting going on with the black hole.”
The new findings “push the limits of the current statistical models,” since those don’t account for infrared flux levels this high, and suggest scientists’ understanding of our galaxy’s central black hole is not up-to-date, the team wrote in the paper.
Scientists think every galaxy has an especially dense, “supermassive” black hole at its center. The proximity of Sgr A* makes it the easiest black hole for scientists to study. The team that discovered this unprecedented flare-up observed Sgr A* for four nights with an infrared camera at the Keck Observatory on Maunakea in Hawaii.
They were hoping to test Einstein’s theory of general relativity by observing how the black hole warped a nearby star’s light. They got what they came for, plus the unprecedented infrared flare.
Do tweeted a timelapse of the event on Saturday.
Here’s a timelapse of images over 2.5 hr from May from @keckobservatory of the supermassive black hole Sgr A*. The black hole is always variable, but this was the brightest we’ve seen in the infrared so far. It was probably even brighter before we started observing that night! pic.twitter.com/MwXioZ7twV
— Tuan Do (@quantumpenguin) August 11, 2019
For three of the four nights of observation, the black hole was in “a clearly elevated state,” Do’s team wrote.
“We think that something unusual might be happening this year because the black hole seems to vary in brightness more, reaching brighter levels than we’ve ever seen in the past,” Do told Vice.
But the researchers aren’t sure what exactly is going …read more
Source:: Businessinsider – Tech