Hidden Black Hole Identified By Sleuthing Japanese Scientists

There might be more than 100 million undiscovered black holes in our universe.

Researchers have found a previously unknown black hole by examing its effects on an interstellar gas cloud. The discovery introduces a new method for identifying other hidden black holes. 


There is thought to be more than 100 million quiet black holes lurking in our Galaxy. Back holes are objects in space with such a strong gravitational pull that everything, including light, is sucked inside. 

Gas cloud pulled by gravitational force

But because they do not emit light they are hard to detect and astronomists must use the effects of their gravitational pull on nearby objects to locate them. The latest black hole discovery was made after a research team under the supervision of Shunya Takekawa at the National Astronomical Observatory of Japan noticed HCN-0.009-0.044, a gas cloud moving strangely near the center of the Galaxy 25,000 light-years away from Earth in the constellation Sagittarius. 

They investigated using ALMA (Atacama Large Millimeter/submillimeter Array) and found that the cloud was swirling around an invisible massive object. Takekawa explains: "Detailed kinematic analyses revealed that an enormous mass, 30,000 times that of the Sun, was concentrated in a region much smaller than our Solar System. This and the lack of any observed object at that location strongly suggests an intermediate-mass black hole. By analyzing other anomalous clouds, we hope to expose other quiet black holes." 

Intermediate mass black hole finally identified

Tomoharu Oka, a professor at Keio University and co-leader of the team, adds, "It is significant that this intermediate mass black hole was found only 20 light-years from the supermassive black hole at the Galactic center. In the future, it will fall into the supermassive black hole; much like gas is currently falling into it. This supports the merger model of black hole growth." 


Watching a Black Hole “Burp” Twice Taught Us More About the Milky Way

Blackholes are usually about 5 times the mass of the Sun or classified as a 'supermassive black hole' which is then millions of times the mass of the Sun. While its a common scientific assumption that small black holes merge and gradually grow into large ones, until now, no intermediate-mass black hole, hundreds or thousands of times the mass of the Sun have ever been identified. 

Studying and understanding black holes are of ongoing concern to many astronomers and physicist who believe they can answer key questions about our universe. Recent research from the US gets us closer to the physics that exist close to the center of a black hole by using the theory called "loop quantum gravity". 


The theory uses quantum mechanics to extend gravitational physics beyond Einstein's theory of general relativity. It originated at Penn State and has been adopted by scientists all over the world to explore new paradigms in modern physics. It is considered to be the best way to analyze extreme cosmological and astrophysical phenomena in parts of the universe, such as black holes.