It’s been a few weeks since the first actual photograph of a black hole was released and the new love affair with the light-sucking space orifices has many people thinking they may not be so bad after all. That may change with the news this week that another group of astronomers has found a black hole so large and powerful that it’s dragging space and time behind it as it moves across its galaxy. Not only that, the black hole is traveling at 60 percent of the speed of light and wobbling as it goes. Is there a galactic speed cop who can pull it over and give it a stellar breathalyzer?
“Typically, radio telescopes produce a single image from several hours of observation. But these jets were changing so fast that in a four-hour image we just saw a blur."
Alex Tetarenko, an East Asian Observatory Fellow, co-authored a new study published in the journal Nature describing new observations of V404 Cygni, a binary system in the Cygnus constellation consisting of a microquasar (a compact region surrounding a black hole) with a mass of about 9 times our Sun and an early K giant star with a mass slightly smaller than the Sun. The "V" in the name indicates that it is a variable star which repeatedly gets brighter and fainter over time. V404 Cygni has been studied extensively since it was discovered in 1989, but it was only recently that study co-author James Miller-Jones from the Curtin University noticed something unusual.
“Like many black holes, it’s feeding on a nearby star, pulling gas away from the star and forming a disk of material that encircles the black hole and spirals towards it under gravity. What’s different in V404 Cygni is that we think the disk of material and the black hole are misaligned. This appears to be causing the inner part of the disk to wobble like a spinning top and fire jets out in different directions as it changes orientation.”
That wobble is what makes the existence of V404 Cygni an Einsteinian moment. In his theory of relativity, Albert E. predicted this phenomenon called frame-dragging which is caused by the black hole spinning faster at its center and pulling spacetime along with it. In this case, it’s traveling so fast that it was a blur to the radio telescopes watching it. In order to see it, the astronomers took 103 high-resolution, low shutter speed radio images each 70 seconds long and strung them together in a video (see it here) and then used it to produce an explanatory animation (see it here).
As always, more research is needed. Study co-author Dr. Gemma Anderson from the International Centre for Radio Astronomy Research (ICRAR) at Curtin University, says more misaligned black holes will undoubtedly be found doing other strange things.
“That could include a whole bunch of other bright, explosive events in the Universe, such as supermassive black holes feeding very quickly or tidal disruption events when a black hole shreds a star.”
Fortunately, they’re too far away to frame-drag us and spacetime behind them. So they won’t mind if some Earth garage band calls itself The Wobbly Black Holes.