THE FIRST BLACK HOLE PHOTO

               
                                                            Black Hole 

                  




The Event Horizon Telescope (EHT) — a planet-scale array of eight ground-based radio telescopes forged through international collaboration — was designed to capture images of a black hole. Today, in coordinated press conferences across the globe, EHT researchers reveal that they have succeeded, unveiling the first direct visual evidence of a supermassive black hole and its shadow.

This breakthrough was announced today in a series of six papers published in a special issue of  The Astrophysical Journal Letters. The image reveals the black hole at the center of Messier 87, a massive galaxy in the nearby Virgo galaxy cluster. This black hole resides 55 million light-years from Earth and has a mass 6.5 billion times that of the Sun.

EHT Telescope 


The EHT links telescopes around the globe to form an unprecedented Earth-sized virtual telescope. The EHT offers scientists a new way to study the most extreme objects in the Universe predicted by Einstein’s general relativity during the centenary year of the historic experiment that first confirmed the theory.




About Blackhole

                                          

A black hole is a region of a spacetime exhibiting such strong gravitational effects that nothing—not even particles and electromagnetic radiation such as light—can escape from inside it. The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole. The boundary of the region from which no escape is possible is called the event horizon.

Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, no locally detectable features appear to be observed. In many ways, a black hole acts as an ideal black body, as it reflects no light.

                                          




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, supermassive black holes of millions of solar masses (M☉) may form. There is a general consensus that supermassive black holes exist in the centers of most galaxies.

How did the scientist imagine it

                          
                              
The astronomers used a technique known as interferometry, which combines radiation from eight telescopes from around the world in a way that it appears as one single telescope capture. What this virtual telescope would capture were traces — electromagnetic radiation — from jets of particles spewed from the event horizons of the black hole. This faint radiation, in the form of mostly radio waves, would have traveled trillions of kilometers and for the telescope to observe them would be the equivalent of trying to snap a picture of an ant from the moon.

How they decided on the black hole

                           



The EHT team decided to target two of the closest supermassive black holes to us – both in the large elliptical shaped galaxy, M87, and in Sagittarius A*, at the center of our Milky Way.

To give a sense of how hard this task is, while the Milky Way’s black hole has a mass of 4.1 million Suns and a diameter of 60 million kilometers, it is 250,614,750,218,665,392 kilometers away from Earth – that's the equivalent of traveling from London to New York 45 trillion times. As noted by the EHT team, it is like being in New York and trying to count the dimples on a golf ball in Los Angeles or imaging an orange on the moon.




General Relativity Proved

The most important initial take-home is that Einstein was right. Again. His general theory of relativity has passed two serious tests from the universe’s most extreme conditions in the last few years. Here, Einstein’s theory predicted the observations from M87 with unerring accuracy and is seemingly the correct description of the nature of space, time, and gravity.

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The measurements of the speeds of matter around the center of the black hole are consistent with being near the speed of light. From the image, the EHT scientists determined that the M87 black hole is 6.5 billion times the mass of the Sun and 40 billion km across – that’s larger than Neptune’s 200-year orbit of the sun.