This image provided by International Centre for Radio Astronomy Research shows the strong stellar wind from the supergiant star pushing the jets launched by the black hole away from the star.International Centre for Radio Astronomy Research/via The Associated Press
For the first time, scientists have measured the instantaneous mind-blowing power of jets blasting from a black hole.
The jet power from this relatively close black hole-star system is equivalent to 10,000 suns, an international research team reported Thursday. They also tracked the jet speed: roughly 540 million kph – half the speed of light.
Located 7,200 light-years away, Cygnus X-1 features not only a black hole – the first one ever identified more than a half-century ago – but a blue supergiant star, its constant companion. A light-year is nearly 9.7 trillion kilometres.
The University of Oxford’s Steve Prabu and his team based their findings on 18 years of high-resolution radio imaging obtained by a global telescope network. He conducted the research while still at Australia’s Curtin University, which led the study published in Nature Astronomy.
Prabu and his colleagues were able to measure the swift power of these “dancing jets” as he calls them, as they were pushed in opposite directions by the star’s wind. The group based its calculations on how much the jets were bent by the stellar wind as well as computer modelling.
Until now, a black hole’s jet power had to be averaged over tens of thousands of years, the researchers said.
Prabu said a key finding is that 10 per cent of all the energy released as matter falls toward the black hole is carried away by the jets.
On the skimpy side as black holes go, the one in Cygnus X-1 is continually pulling gases from its stellar playmate as they orbit one another. Discovered in the 1960s, the binary system is located in our Milky Way’s Cygnus, or swan, constellation.
The supergiant star feeds material to the black hole, giving it “something to ‘eat’ and launch as jets,” Prabu said in an e-mail.
These jets can help scientists better understand how black holes help shape galaxies and other cosmic structures through large-scale shocks and turbulence.
Prabu plans to apply similar techniques to other black holes. “It would be exciting to measure jet power in many more systems,” he said.