A team from France and Belgium have discovered that X-ray flares emanating from the black hole, which is located 26,000 light-years away from Earth, have increased by a factor of three between August 2014 and 2017. The team wrote in their paper published in the online journal arXiv: “Since 2014, the activity of Sgr A* thus increased in several wavelengths.
“Additional multiwavelength data are required to conclude on the persistence of this increase and to obtain clues on the source of this unprecedented activity of the supermassive black hole.”
Further analysis is required to determine what is causing the increase in flares, whether it be the accretion disc – the gas and dust surrounding the black hole – or passing asteroids and other celestial bodies.
Black holes are some of the mysterious and most powerful entities in the universe – but what is known of them is terrifying.
They completely break the laws of physics with their singularity at the centre, which is a one-dimensional point where gravity becomes infinite and space and time become curved.
The only other point in nature where a singularity existed is at the Big Bang.
There are a few ways in which a black hole can form.
Scientists believe the most common instance is when a star, thousands of times the size of the Sun, collapses in on itself when it dies – known as a supernova.
Another way is when a large amount of matter, which can be in the form of a gas cloud or a star collapses in on itself through its own gravitational pull.
Finally, the collision of two neutron stars can cause a black hole.
The gist of all three ways is that a massive amount of mass located in one spot can cause a black hole.
Sagittarius A* has a radius of 22 million kilometres and a mass of more than four million times that of the Sun. In other words, it is very dense.
And because it is so heavy, it has the ability to completely stretch out space-time to a point where one minute on the edge of Sagittarius A* will see 700 years pass on Earth.
Emma Osborne, an astrophysicist at the University of Southampton, told an audience at New Scientist Live: “Anything mass will stretch space-time. And the heavier something is, or the more mass it has, the more it will stretch space-time.
“If you were to stand just outside the event horizon of Sagittarius A*, and you stood there for one minute, 700 years would pass because time passes so much slower in the gravitational field there than it does on Earth.”
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