The first black hole ever detected is more massive than we thought

New observations of the first black hole ever detected have left astronomers wondering what they know about the Universe’s most mysterious objects.

Published today in the newspaper Science, research shows that the system known as Cygnus X-1 contains the most massive stellar mass black hole ever detected without the use of gravitational waves.

Cygnus X-1 is one of the closest black holes to Earth. It was discovered in 1964 when a pair of Geiger counters were carried aboard an sub-orbital rocket launched from New Mexico.

The object was the subject of a famous science bet between physicists Stephen Hawking and Kip Thorne, with Hawking betting in 1974 that it was not a black hole. Hawking conceded the bet in 1990.

In this latest work, an international team of astronomers used the Very Long Baseline Array – a continent-sized radio telescope made up of 10 satellite dishes spread across the United States – as well as a smart technique for measuring distances in space.

“If we can see the same object in different places, we can calculate its distance from us by measuring how far the object appears to be moving from the background,” said lead researcher Professor James Miller-Jones of Curtin University and the International. Center for Research in Radio Astronomy (ICRAR).

“If you hold your finger in front of your eyes and look at it from one eye at a time, you’ll notice that your finger seems to be jumping from one place to another. It’s exactly the same principle.

“For six days, we observed a full orbit of the black hole and used observations taken from the same system with the same array of telescopes in 2011,” said Professor Miller-Jones. “This method and our new measurements show that the system is further away than previously thought, with a significantly more massive black hole.”

Co-author Prof Ilya Mandel of Monash University and the ARC Center of Excellence for the Discovery of Gravitational Waves (OzGrav), said the black hole is so massive that it calls into question the way astronomers thought they were training.

“Stars lose mass in their surrounding environment due to stellar winds blowing across their surface. But to make a black hole this heavy, we need to reduce the amount of mass bright stars lose in their lifetime,” did he declare.

“The black hole in the Cygnus X-1 system began life as a star about 60 times the mass of the Sun and collapsed tens of thousands of years ago,” he said. . “Incredibly, it orbits its companion star – a supergiant – every five and a half days just one-fifth the distance between Earth and the Sun.

“These new observations tell us that the black hole is more than 20 times the mass of our Sun – a 50 percent increase from previous estimates.”

Xueshan Zhao is co-author of the article and holds a PhD. student candidate at the National Astronomical Observatories – part of the Chinese Academy of Sciences (NAOC) in Beijing.

“Using the updated measurements of the black hole’s mass and its distance from Earth, I was able to confirm that Cygnus X-1 spins incredibly fast – very close to the speed of light and faster than any other black hole found to date, “she said.

“I am at the start of my research career, so being part of an international team and helping to refine the properties of the first black hole ever discovered has been a great opportunity.”

Next year, the world’s largest radio telescope, the Square Kilometer Array (SKA), will begin construction in Australia and South Africa.

“Studying black holes is like shedding light on the best kept secret in the Universe – it’s a difficult but exciting area of ​​research,” said Professor Miller-Jones.

“As the next generation of telescopes comes online, their improved sensitivity reveals the universe in greater and greater detail, leveraging decades of effort by scientists and research teams around the world to better understand the cosmos and the exotic and extreme objects that exist.

“Now is the perfect time to be an astronomer.”

Provided by the International Center for Research in Radio Astronomy