The supermassive black hole in the center of the Milky Way is usually calm, but in May astronomers surprised them with an unprecedented explosion of infrared light.
The supermassive black hole closest to Earth, Sagittarius A * or Sgr A *, was suddenly found 75 times brighter than normal on May 13 for two hours in the near infrared range of the light spectrum.
According to a new publication published on August 5 in arXiv, a Cornell University archive of scientific papers that have not yet been peer-reviewed, this was the brightest flash of lightning the scientist has ever seen in 20 years of the black hole – and twice as bright as any previously recorded.
"The black hole was so bright I first thought it was the star S0-2 because I had never seen Sgr A * so bright before," said Tuan Do, an astronomer and lead author of the newspaper, to ScienceAlert. "I knew almost immediately that there was probably something interesting going on with the black hole."
The new findings "are pushing the boundaries of current statistical models," since they are not responsible for such high levels of infra-red flux, suggesting that scientists' understanding of the central black hole of our galaxy is not up-to-date Team wrote in the newspaper.
Scientists believe that every galaxy has a particularly dense "supermassive" black hole in its center. The proximity of Sgr A * makes it the simplest black hole for scientists. The team, who discovered this unprecedented flare, watched Sgr A * for four nights with an infrared camera in the Keck Observatory on Mauna Kea in Hawaii.
They wanted to test Albert Einstein's general theory of relativity by watching the black hole distort the light of a near star. They got what they wanted and the unprecedented infrared light.
Tweeted a time lapse of the event on Saturday.
For three of the four nights of observation, the black hole was in a "significantly elevated state," wrote Do & # 39; s team.
"We believe something unusual could happen this year as the black hole's brightness appears to vary more and reach lighter levels than ever before," Do told Vice.
But researchers are not sure what's going on.
In black holes, matter is packed in a tiny space, which gives them an extremely strong gravity – Sgr A *, for example, has the mass of 4 million suns. The attraction of a black hole is so strong that even light can not escape. Therefore, researchers must observe the infrared or X-ray light that comes out of the black hole and interacts with nearby gases and stars.
The researchers believe that such an interaction could have caused this bright flash. In particular, an interaction with a nearby star passing near Sgr A * in 2018 could have disrupted the gas flow at the edge of the black hole's grip.
They also pointed to a cloud of dust that passed near Sgr A * in 2014 but was not torn apart as dramatically as astronomers had expected. The brightness could be a "delayed reaction," they wrote.
In 2013, scientists discovered an equally mysterious X-ray flash-up of Sgr A * that was 400 times brighter than the normal levels of X-ray exposure.
Scientists should continue to monitor Sgr A * to see if it undergoes significant changes, wrote Do's Team. Further research could also be used to update models of the regular flow of black hole radiation levels.
"This summer, many astronomers are watching Sgr A *," Do told Vice. "I hope we can get as much data as we can this year before the sky region with Sgr A * appears behind the sun and we will not be able to see it again until next year."