April 17, 2019.
Black holes were thought to be impossible to be seen with the human eye. In fact, they’ve never been seen before. The physics behind them already make them complicated objects with little data representing them. However, on Wednesday, April 10th, the first ever real image of a black hole was released to the public. This is huge and here’s why.
The Event Horizon Telescope, which is eight ground-based radio telescopes in collaboration with one another was specifically built to capture images of black holes. On Wednesday, April 10th, researchers for the EHT unveiled the very first real image of a black hole. This cosmic object resides in the Messier 87 galaxy, which is in the Virgo galaxy cluster roughly 55 million light-years from Earth. The black holes mass is 6.5 billion times larger than our sun.
This image shows a bright ring made of plasma and gas and a dark spot in the middle. To explain the picture, the dark spot is actually a shadow. But that shadow represents the point of the black hole where a region of space and even time has collapsed in on itself, forming one single point of infinite density. This point has such a strong gravitational effect that light can’t escape from within it. This point is called the Event Horizon. So when you observe the black spot on the image itself, know that there is light and lots of matter in there, we just can’t ever see it. It has sunk down into the black hole and is gone from the observable universe.
Secondly, the bright ring of light surrounding the dark spot is called the photon orbit. It’s actually 2.5 times larger than the actual Event Horizon. Any light that travels beyond this orbit could potentially escape the black hole if there was something to reflect it back though it’s unlikely. You may notice that some of the ring is quite bright and this is because the matter that is in it is being torn apart at very high temperatures, in billions of degrees while being swallowed by the black hole. Though the bottom of the ring is much brighter and that is because that light is moving toward us. The light in this image is coming from all directions. The back hole takes space and time and wraps it so much that the light can orbit it in a circle.
The telescope that captured the image can only observe radio frequencies on the electromagnetic spectrum. So, the light around the black hole is transparent to those radio waves, allowing us to see through all of the gas which is attempting to get through the Event Horizon. There was so much that had to go perfectly right in order for this picture to come about. To share, the black hole has to have some radiation emanating from its outskirts and two that radiation had to reach Earth without being knocked off of its course.
Also, eight observatories around the world had to sync up and adjust their clocks to a specific degree. At any given point, something could have gone wrong, even something absurdly small. If that were the case, this historical image would not be here.
The significance of this picture is that it allows researchers to better analyze and understand black holes. They can also study theories relating to gravity. This is a major accomplishment in the field of science. Hopefully soon, the team working with the Event Horizon Telescope will snap another beautiful image of these very strange, mysterious astronomical objects.