BLACK HOLE

         Black holes are a massive holes that have strong gravitational field that can not allow a light to pass through it and it was explained based on the general relativity , the boundary of the region from which light cannot escape is called event horizon.In many ways black hole act as a block body ,block body can't reflect the electro magnetic waves and it temperature is inversely proportional to its mass so they are hard to observe.

General relative theory 

           

     Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed, it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, super massive black hole of millions of solar masses  may form. There is consensus that supermassive black holes exist in the centers of most galaxy

The presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. Matter that falls onto a black hole can form an external accreation disk heated by friction, forming quaseras, some of the brightest objects in the universe. Stars passing too close to a supermassive black hole can be shred into streamers that shine very brightly before being "swallowed." If there are other stars orbiting a black hole, their orbits can be used to determine the black hole's mass and location. Such observations can be used to exclude possible alternatives such as neutron stars. In this way, astronomers have identified numerous stellar black hole candidates in binary system ina established that the radio source known as sagittraseA*, at the core of the milky way galaxy, contains a supermassive black hole of about 4.3 million solar mass.

First Image:

Black hole M87

                    

                  

          In April 10 ,2016 evening a history changing black hole picture was released but there is a question how scientist made it possible ? There is lot of hard work behind this picture

They konw telescope that works based on light is not worth to see the black hole so they tie up with most of the observation company to analyse the black hole they implanted 8 telescope all over the world and they named as evant horizon  have that the ability to observe radiations from black hole and  they analyses each part of black that several light years away for earth which mass~ 7 million times then the sun that was analyse that at same atomic clock time and the radio singels was transmitted into electric signels and its take 2 years to analyse the data to form black hole picture that where there is high radiation are marked as bright areas and low radiations are marked as dark areas by this works they got a picture of M87 black hole....