A supermassive black hole in the Milky Way is “destroying” space-time. “Like a football”

The existence of a supermassive black hole in the center of the Milky Way has been suspected for a long time, but we received the first “tangible” evidence in May 2022, when scientists managed to obtain an image taken by the Event Horizon Telescope. A powerful object with a mass of approximately 4.31 million solar masses – although relatively close to us – still hides many secrets. But one of them has just been solved.

The massive black hole at the center of the Milky Way galaxy is dragging space-time with it

According to a new study led by American astronomer Ruth Daly of Penn State University, the black hole at the center of the Milky Way galaxy is dragging space-time (by definition, a set of events located in four dimensions) with it in a surprising way.

Scientists confirmed that Sagittarius A* rotates quickly (around its own axis), which was calculated, among others, thanks to observations of X-ray emissions from the object’s vicinity using the Chandra space telescope. According to the authors of the study, the rapid rotation of the black hole causes the Lense-Thirring effect, theoretically predicted by Josef Lense and Hans Thirring back in 1918.

Put simply, a non-rotating black hole – as a very massive object – symmetrically bends the space-time in which it is located. Sagittarius A* – as it rotates at enormous speed – not only distorts, but also drags space-time along with its rotation, completely distorting it.

Thanks to this rotation, Sagittarius A* radically changes the shape of space-time in its neighborhood. However, if we have a rapidly rotating black hole, the space-time around it is not symmetrical – the spinning black hole drags all of the space-time with it… crushes it, making it look a bit like a football

– said Ruth Daly, quoted by CNN.

An extremely important discovery. It will help us understand how black holes are born

This behavior of the black hole does not affect the Earth and the Solar System, because Sagittarius A* – although it is located in the center of our galaxy – is still about 26,000 years away. light years away. Explaining the phenomenon, however, is of great importance for astrophysicists who for years have been wondering what the spin (i.e. rotation rate) of “our” supermassive black hole is.

The spin of a black hole is given in the range from zero (no rotation) to one (rotates with the maximum value for its mass). Researchers calculated that Sagittarius A* has a spin ranging from 0.84 to 0.96, which is a very high value. For comparison, the supermassive black hole M87* (known from the first-ever “photo” of a black hole published in 2017) at the center of the Virgo A galaxy spins at a similar speed, but – as it has a much larger mass (6.5 billion Suns) – its spin is close to maximum (1).

The lead author of the study explains that knowing the black hole’s rotation value allows us to better understand how such objects are created. This is extremely important because although the way in which small black holes (stars) are formed has been known for a long time, we are still not sure how these most powerful objects, with a mass of millions or billions of solar masses, are born.