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.
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