Weird Black Hole Shoots Light Speed Plasma Jets
We have been learning a lot about black holes lately from what they look like to where they may or may not be. But despite us getting more familiar with these powerful objects - they never fail to surprise.
Take the black hole called V404 Cygni, that’s located 7,800 light-years away, in the constellation of Cygnus. In 2015 telescopes captured the hole as it rapidly began to devour material from a star over the course of a week.
The incredible phenomena provided astronomers with so much information they are still analyzing it.
Their recent work has uncovered a super interesting occurrence: relativistic jets - beams of ionized matter accelerated close to the speed of light - wobbling so fast their change in direction can be seen in mere minutes.
As they pivot they exhume high-speed clouds of plasma.
Weird black hole baffles astrophysicists
"This is one of the most extraordinary black hole systems I've ever come across," said astrophysicist James Miller-Jones of the International Centre for Radio Astronomy Research (ICRAR) at Curtin University in Australia.
V404 Cygni is a system made up of a black hole about nine times the mass of the sun and a companion star an early red giant slightly smaller than the Sun.
Companion star might be a bit of a stretch though as the black hole is actually slowly consuming the red giant.
The material around the star is being pulled away and is orbiting the black hole, creating a disc of matter, much like the way you see water form a vortex around a drain.
Jets due to misalignment
Scientist note that the closest areas of the disc are dense and hot and that as the black hole devours the star it shoots out powerful jets of plasma, presumably from its poles.
Scientists still don’t know a lot about jet production by black holes, but the ones generated by V404 Cygni are even stranger as they are being emitted at such different timescales and velocities up to 60 percent of the speed of light.
"We think the disc of material and the black hole are misaligned," Miller-Jones said.
"This appears to be causing the inner part of the disc to wobble like a spinning top and fire jets out in different directions as it changes orientation."
The researchers use the analogy of a spinning top that is slowing down to explain what is going on. The change in the rotational axis of a spinning body is called precession.
Spacetime gets dragged
Thanks to Albert Einstein we have a way to understand this idea through a theory called frame-dragging. As the black hole spins its gravitational field is so intense it actually raga spacetime with it.
So to break that down in the case of V404 Cygni, the accretion disc (the mater pulled from the star) is about 10 million kilometers (6.2 million miles) across.
But the black hole's rotational axis misalignment with this disc has warped the inner few thousand kilometers of said disc.
Frame Dragging effect tugs the warped part of the disc along with the black hole's rotation which in turn send the jets peeling off in all directions.
The discovery was a shocking and brilliant breakthrough for the team.
"We were gobsmacked by what we saw in this system - it was completely unexpected," said physicist Greg Sivakoff of the University of Alberta.
"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 team's research has been published in Nature.