Astronomers are constantly investigating and collecting information on any objects in space that have not yet been cataloged. In the course of doing this, they find and identify galaxies, nebulae, novas and, of course, black holes. They just "turn up" frequently as part of the never-ending search of the universe and the objects in it.
specifically, "astronomers" that study black holes are called cosmologists.
Yes, black holes are known and regarded by many scientists, astronomers, and physicists.
Black Holes
Astronomers
you go to a hole that's black and tell people about it.
Astronomers think that the areas around black holes suck everything in like when a tub drains. But black holes are large amounts of matter that is packed into a small area.
Black holes do not emit light, so we cannot observe them directly
Astronomers say that there are several, possibly many, black holes, all a long way from Earth.
Since black holes do not put out any light, we cannot see them. However, we can see the effect that they have on the area of space around them. Since black holes have extremely high gravity, they pull in surrounding material at very high speeds, causing this material to become very hot and emit X-rays. By finding this very hot material which is spiraling into black holes, astronomers can locate where some of them are. Also, astronomers study the motions of objects in space to see where there is material that might be moving as if a black hole were affecting it. So far, evidence had been found for the existence of black holes in the centers of several large galaxies, and in binary star systems (where two stars orbit each other).
Astronomers believe that there are black holes, but I will add that they have only been observed indirectly at great distances, so it may be that the interpretation of our observations will change in the future.
Although the disciplines may overlap with others, it's safe to say that generally astronomers, physicists and astrophysicists study black holes; particle physicists study particles.
While black holes give off radio waves, the fact that no light can escape, or be reflected off of, black holes makes them completely invisible to any regular light-capturing device.