Astro-physicist or simply astronomer would probably be the most accurate title.
Stephen Hawking did.
Stephen Hawkin
He studied more about black holes.
Black holes are distant objects found usually in the center of galaxies; therefore they are studied by astronomers, using telescopes, just as all astronomical objects are studied. Of course, black holes are studied indirectly. They do not emit radiation (or not enough radiation to view; there is Hawking radiation) but they have a strong effect on other nearby objects, which can be observed.
That most likely refers to Stephen Hawking.
Astronomer and physicist Karl Schwarzschild provided the first exact solutions to Einstein's field equations in the year the latter's General Theory was published (1915). Spherically symmetric non-rotating black holes are sometimes called Schwarzschild black holes.
An astronomer studies celestial bodies, which include stars, planets, moons, comets, and galaxies.
It depends on what you're studying besides black holes. If you're studying planets along with black holes, you could be an astrophysicist. Or, if you're studying atoms along with black holes, you could be a theoretical physicist. Just a few examples.
They are studied by astrophysicists which is a branch of astronomy dealing especially with the behavior, physical properties, and dynamic processes of celestial objects and phenomena.
Black holes are also studied in physics, specifically in the field of general relativity. The study of black holes involves understanding their formation, behavior, and effects on surrounding matter and spacetime. Additionally, black holes are also of interest in the field of mathematical physics for their complex geometrical properties.
You could simulate the effects of a black holes event horizon by placing a two-way mirror in front of a black box equipped with a small light. When the light is off in the box, then no light is returning and the internal object cannot be studied. When the light is on in the box, then light is returned and the internal object can be studied.