The Study of the Physics of the Universe or Outer Space. Astrophysics is a combination of the Study of Physics and Astronomy.

Not to be confused with an Aerospace Engineer, or Rocket Scientist.

Often people ask Carlos what is Astrophysics. This is the answer Baron Carlos gives back:

The study of the life, death, and everything that happens in between, of a star, and what it does to the rest of the universe..

It is a difficult science, since there is very little to experiment with.
Which is probably a good thing, since the last thing BaronCarlos would want is to have his old professors be able to massage a real stellar object. (They would cause it to supernova.) (Bad thing).