Astronomers have for the first time have produced a complete description of a black hole, a concentration of mass so dense that not even light can escape its powerful gravitational pull.
Using several telescopes, an international team yielded the most accurate measurements ever of the black hole’s mass and spin rate — in fact, their precise measurements allowed them to reconstruct the history of the object from its birth some six million years ago.
“Because no other information can escape from a black hole, knowing its mass, spin, and electrical charge gives a complete description of it. The charge of this black hole is nearly zero, so measuring its mass and spin make our description complete,” said team leader Mark Reid of Harvard Smithsonian Centre for Astrophysics.
Though Cygnus X-1 has been studied intensely since its discovery, previous attempts to measure its mass and spin suffered from lack of a precise measurement of its distance from earth.
The team’s observations provided a distance of 6070 light years, while previous estimates had ranged from 5800-7800 light years.
“This new information gives us strong clues about how the black hole was born, what it weighed and how fast it was spinning. Getting a good measurement of the distance was crucial,” Reid said. The findings have been published in the Astrophysical Journal Letters.
— PTI