The centre of our Milky Way galaxy is home to a supermassive black hole that is spinning so quickly that it is warping spacetime into an oval form resembling a rugby ball. The result is based on a thorough analysis of X-ray and radio measurements from NASA's Chandra X-ray Observatory, an X-ray telescope in space. The giant black hole, known as Sagittarius A* or Sgr A* is located about 26,000 light-years away from Earth.
"Black holes have two fundamental properties. The first is their mass, or how much they weigh. The second is their spin, or how quickly they rotate. Determining either of these two values tells scientists a great deal about any black hole and how it behaves," NASA explained.
Scientists have been unable to determine Sgr A*'s exact rotational speed, but they are certain that it weighs roughly four million times that of the Sun. This new study utilizes a method based on material movement towards and away from the black hole to calculate the spin rate of Sgr A* using X-ray and radio data.
The results show that the black hole is spinning very fast. The American space agency stated, "Scientists think that it is rotating so quickly that it is warping spacetime around it into a shape that looks like an American football."
The concept of time paired with the three dimensions of space is called spacetime. Although black holes have long been known to have this ability, there is now substantial proof that the black hole in the Milky Way galaxy is doing so.
"Our work may help settle the question of how fast our galaxy's supermassive black hole is spinning. Our results indicate that Sgr A* is spinning very rapidly, which is interesting and has far-reaching implications," said Ruth Daly of Penn State University, who is the lead author of the new study.
The spinning of a black hole also has several other implications. It can act as an important source of energy. Extraction of spin energy from spinning supermassive black holes can result in narrow outflows in the form of jets. Although Sgr A* is not very active right now, this new discovery suggests that it may become more so in the future.
"A spinning black hole is like a rocket on the launch pad," said Biny Sebastian, a co-author from the University of Manitoba in Winnipeg, Canada. "Once the material gets close enough, it's like someone has fueled the rocket and hit the 'launch' button."
According to the space agency, if the properties of the matter and the magnetic field strength close to the black hole change in the future, part of the enormous energy of the black hole's spin could drive more powerful outflows. If the star wanders too close to the black hole, this source material coming from gas or from the remnants of a star will be torn apart by the black hole's gravity.
