Astronomers Spot Distant Black Hole Spinning So Fast That It Warps Space-Time
Some 8,000 light-years from Earth in the Cygnus constellation (“The Swan”), a small black hole weighing just nine times the mass of Earth’s sun is gobbling up a sun-like star. The black hole and its stellar victim are locked together in what astronomers call a binary system and orbit each other once every 6.5 days – with spectacular effects, the National Radio Astronomy Observatory (NRAO) is reporting.
While the black hole may be relatively tiny as far as these celestial objects go – for instance, the supermassive black hole at the heart of the Milky Way galaxy, known as Sagittarius A*, is 4 million times more massive than the sun, per a previous report from The Inquisitr – it does pack a pretty mean punch. Dubbed V404 Cygni, the black hole is continuously siphoning material from its stellar companion, slowly consuming the unfortunate star.
As it often happens in this type of binary system in which a star has the misfortune of sharing its lodgings with a black hole, V404 Cygni is slowly eating away at its neighbor, gradually draining the star of gas and dust. Since the stellar gas and debris is too vast to be devoured all at once, the material swirls around the black hole in a so-called accretion disk – on which V404 Cygni continuously feasts, shooting out X-rays and plumes of hot gas, or plasma, in the process.
This is the common fate that befalls most stars wandering too close to a black hole after getting sucked in by its strong gravity. And, while it’s not unusual for a black hole to spew out an intense amount of radiation and relativistic jets as it munches on a star, as previously covered by The Inquisitr, the emissions coming from V404 Cygni are truly special.
This particular black hole made headlines in 2015, when astronomers observed a massive outburst coming from V404 Cygni. Picked up by NASA’s Swift satellite, the outburst lasted for two weeks and was the first signal of activity detected from the slumbering object in nearly three decades, as reported by NASA at the time.
The event prompted a group of scientists to investigate the black hole and study its emissions. Led by James Miller-Jones, a researcher with the International Centre for Radio Astronomy Research (ICRAR), the team has just published a study in the journal Nature detailing the peculiar nature of the plasma jets being released by V404 Cygni.
According to their findings, the jets of hot gas spewing out of the black hole are unlike anything science has ever encountered before. While astronomers have had the chance to study relativistic jets emitted by black holes in the past – beams of ionized particles traveling close to the speed of light – the streams of particles ejected by V404 Cygni are “wildly wobbling,” notes Space.
In fact, the plasma jets coming from the black hole are moving so fast that they rapidly change orientation in a matter of minutes, tugging at the space around them in the process. Based on their observations, the scientists believe that “this unusually rapid motion could be happening because the black hole’s strong gravity is warping space around it,” states the media outlet.
This Black Hole's Jets Wobble Like Crazy Because It's Warping Space-Time https://t.co/uVqICuSpJe pic.twitter.com/mlUgoMi8QW
— SPACE.com (@SPACEdotcom) April 29, 2019
After monitoring V404 Cygni with the Very Long Baseline Array (VLBA), a massive network of 10 radio telescopes set up all around the world, the team discovered that the plasma jets coming from the black hole “were changing so fast that, in a four-hour image, we saw just a blur,” explained study co-author Alexandra Tetarenko, an East Asian Observatory fellow in Hawaii.
“We’ve never seen this effect happening on such short time scales,” Miller-Jones said in a statement released today by the NRAO.
To get a better view of the black hole, his team snapped a total of 103 images of V404 Cygni, each with an exposure of about 70 seconds, and pieced them together into an animation, thereby obtaining a short movie of the active black hole. The visualization revealed that the object was wobbling like a spinning top, pulling space-time around with it and redirecting its relativistic jets in the process, reports Gizmodo.
“We were gobsmacked by what we saw in this system — it was completely unexpected,” said study co-author Greg Sivakoff, an astronomer at the University of Alberta in Canada.
“Finding this astronomical first has deepened our understanding of how black holes and galaxy formation can work. It tells us a little more about that big question: ‘How did we get here?'”
The results are consistent with Albert Einstein’s general theory of relativity, which predicts that massive objects can warp space-time.
“When such a massive object is spinning, its gravitational influence pulls space and time around with it, an effect called frame-dragging,” detailed the NRAO, which runs the VLBA radio telescope network for the National Science Foundation.
As the black hole feeds on its neighboring star, the innermost portion of its accretion disk – which measures 6.2 million miles across in its entirety – is “puffed up” by the intense radiation generated while the ravenous object gorges on its stellar companion. This, coupled with the fact that the black hole’s spin axis is misaligned with the plane of the star, “causes the frame-dragging effect to warp the inner part of the disk, then pull the warped portion around with it,” explained NRAO officials.
“Since the jets originate from either the inner disk or the black hole, this changes the jet orientation, producing the wobbling observed with the VLBA.”