A Weird Black Hole, called V404 Cygni, is Throwing off Wobbly Jets

V404 Cygni is one of the most peculiar black holes known to humanity because the change in direction of its wobbling relativistic jets can be observed in a matter of minutes.

V404 Cygni is actually a binary microquasar system comprising of a black hole, which is about 9 times the mass of our sun. This black hole is slowly devouring an early red giant star that is nearly as big as the star of our solar system. The material of the star is orbiting the black hole in the form of an accretion disc. The closest regions of this disc are incredibly hot and radiant as powerful jets of plasma are being released from the poles of the black hole.

This mysterious black hole is located at a distance of 7,800 light-years from Earth as it lies in the constellation of Cygnus. In 2015, a number of telescopes around the world observed the event when it woke from its dormancy to start eating up the material from a neighboring star. The observations that lasted for a week were able to collect so much data that scientists are still analyzing it, after a period of 4 years. Recently, astronomers were able to discover that the relativistic jets from V404 Cygni are wobbling so fast that they can change direction in minutes. James Miller-Jones, an Astrophysicist from the International Center for Radio Astronomy Research (ICRAR), explained the system in the following words:

“This is one of the most extraordinary black hole systems I’ve ever come across.”

Wobbly Jets of V404 Cygni

Although astronomers are not sure about the exact mechanism that leads to jet production, most of them believe that the material from the innermost rim of the accretion disc is funneled along the magnetic field lines of black holes to produce them. These lines accelerate the particles of the jets before launching them into the surrounding space at outrageous speeds. Having said that, the jets of V404 Cygni have a class of their own as they shoot out in different directions at rapidly changing timescales and they travel at a speed of up to 60% of the speed of light. Miller-Jones referred to that idea by saying,

“We think the disc of material and the black hole are misaligned. 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.”

Dragging Space-time

The researching team mentioned that it resembles a spinning top that starts to wobble while it’s slowing down. They took help from Einstein’s Theory of General Relativity to explain V404 Cygni. He predicted an effect, called Frame-dragging, which suggests that the gravitational field of a spinning black hole is so strong that it essentially drags space-time with it.

The theory proposed by the team of Miller-Jones explains that the 10-million-kilometers-wide accretion disc of V404 Cygni is misaligned with the rotational axis of the black hole. Consequently, inner few thousand kilometers of the disc are twisted out of shape. The frame-dragging effect of the black hole pulls the warped part of the disc with it which results in the wobbling jets that were observed by the astronomers. Miller-Jones acknowledged that this is the only mechanism they could think of that can explain the rapid precession we see in V404 Cygni.

Traditional Radio Telescopes

The radio telescopes that are traditionally used for imaging space were practically useless for observing V404 Cygni because they need long exposures (several hours at a time) for examining their target. As a result, the researching team had to come up with a different technique to capture this amazing system. They took 103 separate images with exposure times of just 70 seconds and then combined them together to create a movie, which showed wobbly jets. Greg Sivakoff, a Physicist at the University of Alberta, expressed his delight about the discovery and said,

“We were gobsmacked by what we saw in this system – it was completely unexpected. 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?’”

You can have a look at this peculiar black hole in the following video: