An incredibly rare close shave between a red giant star and a black hole has been photographed by a powerful scientific instrument operated by both NASA and ESA. The happening unveils a major quarter in a cosmic story that will probably continue for a trillion years.
The lethal event is taking place in the galaxy GSN 069, located approximately 250 million light-years away from Earth. The black hole is about 400,000 times the mass of our Sun, which is actually making it rather small is we were to consider the supermassive black hole standards, but it is still frightening in scale.
Stripped Away Repeatedly
The red giant star, captured by the black hole’s powerful gravitational pull, had its exterior layers of hydrogen torn away, leaving only the nucleus of the star, the white dwarf, behind to be the witness of the close call for us through bursts of X-rays.
“In my interpretation of the x-ray data, the white dwarf survived, but it did not escape,” said Andrew King of the University of Leicester in the UK, who analyzed the data from the ESA and NASA. “It is now caught in an elliptical orbit around the black hole, making one trip around about once every nine hours.”
Simply put, the leftover white dwarf rotates around its attacker three times per day, as the black hole pulls its layers away whenever it comes too close. Every time the black hole strips away more matter from the star, it emits a burst of X-rays observable by NASA’s Chandra X-ray Observatory and the ESA’s XXM-Newton.
The astronomers are also expecting the release of gravitational waves by the black hole and white dwarf as they continue this vicious and deadly dance. Although the star’s decrease in mass will trigger its orbit to round out and spread, researchers believe it will only have one result: definite doom.
“It will try hard to get away, but there is no escape. The black hole will eat it more and more slowly, but never stop,” explained King. “In principle, this loss of mass would continue until and even after the white dwarf dwindled down to the mass of Jupiter in about a trillion years. This would be a remarkably slow and convoluted way for the universe to make a planet!”
Researchers have captured and analyzed numerous instances of black holes ripping apart stars until nothing remained, and also evaluated the awful aftermath, but there have been only a few instances of semi-survival such as the one spotted now.