The following is provided by Wikipedia:

Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temprature, and chemical composition) of celestial bodies such as stars, galaxies, and the interstellar medium, as well as their interactions. The study of cosmology is theoretical astrophysics at scales much larger than the size of particular gravitationally-bound objects in the universe.

Because astrophysics is a very broad subject, astrophysicists typically apply many disciplines of physics, including mechanics, electromagnitism, statistical mechanics, thermodynamics, quantom mechanics, relavility, nuclear and partical physics, and atomic and melecular physics. In practice, modern astronomical research involves a substantial amount of physics. The name of a university's department ("astrophysics" or "astronomy") often has to do more with the department's history than with the contents of the programs. Astrophysics can be studied at the bachelors, masters, and P.H.D levels in erospace engeneering, physics, or astronomy departments at many universities.

Since this is a science category I wanted to post this group. Here you can talk about astronomy like: Stars, planets, constellations, globular clusters, black holes, planetary nebula, supernovas, neutron stars, binary stars,  black dwarfs, and many other different kinds of cosmos out there. Even death by stars.