Astronomy is a branch of fundamental physics.
Astronomy is NOT to do with memorizing names of stars and of constellations. There are higher temperatures, higher energies, higher vacuums, higher pressures, regions more dense, greater distances, and longer intervals of time available. Astronomers observe at all wavelengths where Nature and technology make observations possible. Because of the Earth's atmosphere and its ionosphere, radiation at certain wavelengths can not penetrate to ground-based observatories and so can only be observed from space. By convention, based on tecnology and not on Nature, the spectrum of radiation used by astronomers is divided roughly into the following categories.