Misaligned black hole just 8,000 light years from Earth behaving weirdly
By Alexander J Martin, technology reporter
Scientists have discovered a "misaligned" black hole just 8,000 light years from Earth – and it's behaving in a way that has never been seen before.
Researchers from the International Centre for Radio Astronomy Research (ICRAR) published their findings about the V404 Cygni black hole in the journal Nature.
They have never seen a black hole behaving in such a strange way before – with its spewing radio jets rotating with high-speed clouds of plasma that are erupting out of it in different directions.
The study's lead author, Associate Professor James Miller-Jones, said: "This is one of the most extraordinary black hole systems I've ever come across.
"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 misalignment means that the inner part of the black hole's disk is wobbling like a spinning top, causing the jets to be fired out in different directions as it changes orientation.
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The black hole in V404 Cygni was first discovered in 1989 after a huge outburst of jets and radiation.
According to Associate Professor Miller-Jones, another very bright outburst in 2015, lasting for two weeks, prompted telescopes around the world to tune in and study what was going on.
"Everybody jumped on the outburst with whatever telescopes they could throw at it, so we have this amazing observational coverage," he said.
When the ICRAR team studied the black hole they realised the jets were behaving in a way which had never been seen before.
Normally, jets shoot straight out from the poles of black holes, but these jets have been spotted shooting in different directions at different times – and they were chaging direction rapidly, every couple of hours.
Associate Professor Miller-Jones said this change was because of the accretion disk, the disk of matter around the edge of the black hole that was falling into it.
"The inner part of the accretion disk was precessing and effectively pulling the jets around with it," Associate Professor Miller-Jones said.
"You can think of it like the wobble of a spinning top as it slows down -only in this case, the wobble is caused by Einstein's theory of general relativity."