Black hole’s gravity seen tugging on nearby space
Deborah Byrd in SPACE | April 29, 2019
“We were gobsmacked by what we saw in this system. It was completely unexpected … It tells us a little more about that big question: ‘How did we get here?'”
Artist's Conception
Deborah Byrd in SPACE | April 29, 2019
“We were gobsmacked by what we saw in this system. It was completely unexpected … It tells us a little more about that big question: ‘How did we get here?'”
Artist's Conception
National Radio Astronomy Observatory (NRAO) said on April 29, 2019, that astronomers have spied a relatively modest black hole, which nonetheless features jets of fast-moving material that are wobbling or precessing so fast their change in direction can be seen in only minutes. This sort of wobble – witnessed before among black hole jets, but not on such short timescales – happens in a way that requires an effect of Einstein’s general theory of relativity. It happens because, as the black hole spins, its powerful gravity is dragging along nearby space itself.
James Miller-Jones of Australia’s International Centre for Radio Astronomy Research led researchers in this study. He and his team employed the Very Long Baseline Array, a system of 10 radio telescopes located in various U.S. states and remotely operated from Socorro, New Mexico. They studied a black hole known as V404 Cygni, which isn’t a supermassive black hole lodged in the center of a galaxy, but just an ordinary nine-solar-mass black hole, located only 8,000 light-years from Earth in our Milky Way galaxy. NRAO said in a statement:
The black hole is drawing in material from a companion star with a mass about 70 percent that of our sun. As the material streams toward the black hole, it forms a rotating disk, called an accretion disk, surrounding the black hole.
In such systems, the disk becomes denser and hotter with decreasing distance from the black hole. Either the innermost portion of the disk or the black hole itself launches jets of material outward away from the disk. The astronomers said V404 Cygni’s jet material moves as fast as 60 percent of the speed of light.
In such systems, the disk becomes denser and hotter with decreasing distance from the black hole. Either the innermost portion of the disk or the black hole itself launches jets of material outward away from the disk. The astronomers said V404 Cygni’s jet material moves as fast as 60 percent of the speed of light.
These jets are precessing or wobbling so fast, the scientists said, that Einstein’s general theory of relativity is needed to explain them. According to Einstein, massive objects like black holes distort space and time. Further, when such a massive object is spinning, its gravitational influence pulls space and time around with it, an effect called frame-dragging.
More images and a video animation are available at ICRAR's (International Centre for Radio Astronomy Research) Web site:
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https://www.icrar.org/CygniEinstein to the rescue once again! - ilan