What is the first thing that comes to mind when you hear the term black hole Most people know of the term but do not understand what it is We can understand what stellar balck holes are by examining the evidence The proof can be found by the knowledge of a star s life cycle and properties and from x rays emissions of light as it falls into a black hole First we need to understand what a stellar black hole is A black hole used to be a massive star in space time however due to the intense pull of gravity on it not even the fastest thing in the universe light can escape it Gravity s works to fight the pressure created by the hot core of the star The pressure produced balances the gravitational force and steadys the star until there are no more nuclear reactions allowing gravity to win This causes the star to collapse in on itself When the core of a massive star collapses on itself a blast wave is created and causes an implosion which forms a black hole Black holes become larger as they draw more mass in However we can not visibly see its size expand but the boundary around the back hole where nothing can escape becoming more dense This transformation does not happen to every star though less massive stars form neutron stars which are not big enough to entrap light The amount of mass a star has determines if it would become a neutron star or black hole Second another piece of evidence is x rays emissions of light as it falls into a black hole We are able to see this by the event horizon The event horizon is the distance from the singularity where gravity is so strong that not even the quickest thing in the universe can escape its gravitational pull Light in the event horizon is unable to escape which means that you can not view any light if you are outside of the horizon Now we are able to calculate how far the event horizon is from the center of a black hole by x rays X rays emit a red color when they fall into a black hole which causes them to create a ring of light Examining the ring size from the x rays emission allows us to measure the size of the ring borderlining the event horizon and the mass of the black hole All together these pieces of evidence prove the existence of black holes The center of the event horizon is the point where a black hole stays and we can prove this by analyzing a star s life cycle When stars run out of fuel gravity overcomes their mass turning it into a black hole The gravitational pull that comes from a black hole which created an event horizon shows red color surrounding the event horizon ring With all this in mind we are able to understand the evidence of black holes