This is an imagination of the X-1 Cygnus black hole. X-1 emits X-rays as it absorbs material from its blue supergiant, a partner star that is about half the distance between the Sun and Mercury. Provided by the International Radio Astronomy Research Center
The black hole X-1 Cygnus was the first black hole discovered by mankind. After a astronomical object emitting strong X-rays was identified in the constellation Cygnus in 1964, controversy arose over whether a black hole was correct. Dr. Stephen Hawking, a genius physicist who is famous for black hole research, and Kip Thorn, a 2017 Nobel Physics Prize winner, an emeritus professor at the University of California, USA, even made a bet on whether or not X-1 Cygnus was a black hole in 1974. Afterwards, observational data proved the existence of a black hole, and Dr. Hawking admitted his defeat in 1990. The anecdote that gave Sohn a year’s worth of adult magazine’Penthouse’ is still famous.
Human observation technology, which was difficult to detect whether a black hole was 30 years ago, has now developed to the extent that it can accurately determine its location and mass. Researchers from Australia, the United States, and China, including Korean astronomers, reported that a precise measurement of the X-1 Cygnus black hole found that the distance from Earth was 7200 light-years away from the previously known 6100 light-years. Local time). The researchers also reported in the same paper that they found that the mass of the black hole is 21 times the mass of the Sun and 1.5 times the mass of the previously known mass. In this study, Do-young Byun, senior researcher at the Radio Astronomy Headquarters at the Korea Astronomical Research Institute, senior researcher Jeong Tae-hyun, and postdoctoral researcher Kim Jeong-suk, participated in a study to precisely measure the location of the black hole.
X-1 Cygnus is a star mass black hole created when the star burns and consumes all of its internal hydrogen energy and contracts because it cannot overcome gravity. It is estimated that the star, which is 60 times the mass of the Sun, has collapsed. Among black holes, it is relatively small. ‘M87 Virgo’, a black hole that first revealed its existence in the world in 2019, is a supermassive black hole that is 6.5 billion times the mass of the Sun.
X-1 has a’pair star (companion)’, which is a celestial circle that revolves together. The two celestial bodies orbit each other once every 5.6 days at a distance of one fifth between the sun and the earth. The black hole quickly absorbs the material emitted by the companion star and emits X-rays. Astronomers look at this X-ray to predict the existence of a black hole.
The research team estimates the location and size of the black hole by observing radio signals from the black hole from May 29 to June 3, 2016 with an ultra-long line radio interferometer (VLBA) that connects 10 radio telescopes spread across the U.S. mainland and Hawaii. did. Trigonometry was used to estimate the position of another object based on the position of two objects. Tae-Hyun Jeong, a senior researcher at the Astronomical Research Institute, said, “By observing the surrounding area where the black hole is supposed to exist for a long period of time, we alternately observe the precise location of the galaxy and the black hole every day, and substitute the movement of the earth to estimate the location of the black hole.”
The observed mass of X-1 broke the existing star formation theory. Astronomers have predicted that a star’s mass is reduced to about 5 to 15 times the mass of the Sun due to the stellar winds emitted from the star’s surface as a star becomes a black hole. James Miller Jones, a professor at Curtin University, Australia, who led the study, said, “A heavy star is a black hole. “It is evidence that reveals the process of star formation and growth until it is formed.”
Korea also continues to observe black holes. Cheon Mun-yeon is doubling the performance of the Korea Space Radio Monitoring Network (KVN) by building the fourth radio telescope in Korea in Pyeongchang, Gangwon-do. KVN was used to verify data from other telescopes during the’Ecident Horizon Telescope (EHT)’ project that photographed the’M87 Virgo’, the black hole in which mankind first recorded video. The fourth radio telescope, scheduled to be built by 2024, is capable of observing high frequencies of 230 gigahertz (GHz), and is expected to be used for video observation, the next project of the EHT, which photographed M87 Virgo. Senior Researcher Jeong said, “We plan to continue black hole research, such as observing X-3, another black hole in Cygnus with KVN.”