Black hole Cygnus X-1. /Photo = Provided by Korea Astronomical Research Institute
The black hole’X-1 Cygnus’, the first black hole discovered by mankind, was found to be farther away and heavier than originally known.
An international joint research team including the Korea Astronomical Research Institute announced on the 19th that it has succeeded in measuring the precise location of the X-1 Cygnus black hole with a U.S. ultra-long-air interferometer (VLBA) telescope connected to 10 radio telescopes.
X-1 Cygnus was first discovered in 1964, where a black hole and a blue supergiant (a high-energy star with a mass of up to 100 times that of the Sun and a luminosity of up to 1 million times that of the Sun) form a binary star system.
The researchers found that the distance to the X-1 Cygnus black hole is about 7200 light-years away from the previously known about 6,100 light-years. They also found that the mass of a black hole is 21 times the mass of the Sun, which is about 50% heavier than the known mass.
The research team observed radio signals from the black hole X-1 Cygnus, while using a triangular parallax method to precisely measure the distance from Earth.
Black hole X-1 Cygnus is a’star mass black hole’ that is born at the end of the star’s evolution, and is expected to contribute to clarifying the growth process from the evolution of heavy stars to black holes.
“X-1 Cygnus was a much heavier star than the previous hypothesis,” said Ilya Mandel, a professor at Monash University in Australia, co-author of this paper. “This indicates that the mass loss caused by stellar winds during the evolution of the star was relatively less. I mean,” he said.
Dr. Tae-Hyun Cheon said, “We plan to continue research on X-3 Cygnus, a subsequent black hole, using the Korea Space Radio Observation Network (KVN), which is the only one in the world that can simultaneously observe four frequency bands.”
The results of this study were published in the prestigious international journal’Science’ on February 18th.
Reporter Lee Mi-kyung, Hankyung.com [email protected]
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