How Do You See An Object That Absorbs Light?

Scientists manage to image the black hole residing at the centre of our galaxy.

These are the announcements in Cosmology I absolutely adore, largely because they speak of the essence of Physics in making observations through indirect analysis. What I mean is a scenario such as identifying the weight of an object by measuring how much noise it makes on impact following a drop through a known distance.

Here is the article describing how scientists managed to create an Earth sized radio telescope to interpolate the images we see. The bright spots are regions where matter is accelerated to high speeds as it approaches and then passes the black hole`s event horizon.

https://eventhorizontelescope.org/blog/astronomers-reveal-first-image-black-hole-heart-our-galaxy