Question

Astronomy can best be described as a/an

Answer 1

The study of heavenly bodies.

How that differs from astrophysics, astro dynamics, cosmology, etc., I'm not entirely sure.

Answer 2

as·tron·o·my- the branch of science that deals with celestial objects, space, and the physical universe as a whole. That's the definition hope it is what you need and that it helps:)