It is suspected that a black hole exist at the centre of our galaxy, the Milkyway. This is due to fact that strong radio waves from the same location of the galaxy led the scientists to believe in the black hole.
Location of the black hole
In the bordering constellations of the Saggitarus and Scorpius, there is found to originate strong radio waves which could only be there due to a black hole. Black holes are theoritized a remnants of huge stars that died out because all the fuel required to shine and thrive got expended.
Stars that donot form black holes
Stars are of various sizes. All stars use fusion of hydrogen gasses to create energy and new form of matter. Take for instance the stars nearly the size of Sun. These types of stars towards the end of their life, when all the hydrogen gets converted into helium seems to get desperate to survive. They start fusing the available helium to form carbon atoms, and by this time the star cools as further fusion of atoms beyond hydrogen could not generate enough energy in terms of heat or light. The dense core at the center pull the lighter matter on the periphery and the stars reduce in size and takes a red hue or white hue and ultimately stops generating light and becomes a black dwarf. These stars do not form black holes.
Stars that do form black holes
Stars bigger than the sun have greater mass and size. When they run out of hydrogen, they fuse the available helium atoms to create heavier elements of lithium, bellylium, carbon, and fusing carbon to produce oxygen and then goes on to form iron, cobalt, Nickel and other heavier elements. The process of fusing the lighter atoms to create heavier elements does not create enough energy to survive and the heavier core of the star pull the outer surface to its center and the whole mass condenses to an unimaginably smaller mass. This is also called a neutron star.
Black holes have a great appetite for matter
This highly condensed mass or the singularity of gravity a the center of super heavy matter is so powerful that light fails to escape. This ultimately is called black hole, although there is no hole or cavity in the dead condensed star. The black hole only emanates radio waves. It has the ability to suck in matter. Any planet, comet or asteroid matter will be sucked in should it come near to it.
Event Horizon Telescope
These radio waves are captured by Event horizon telescope. EHT is a collection of powerful antennas arranged in an array thousands of kilometers apart to capture the radio waves from space. Radio waves collected on these antennas are converted into data and sent to a supercomputer to analyze the features of the source and how the distance from earth.
An attempt to see the elusive
Theoretically, it is not possible to see the black hole as there will be no light the come out from the dead neutron star Saggittarus A. An attempt by NASA to convert the interpreted radio waves captured by the ETH will help the world to visualize the black hole.