It encompasses the study of:

* Stars: Their formation, evolution, properties, and interactions.

* Planets: Their formation, composition, atmospheres, and potential for life.

* Galaxies: Their structure, evolution, and interactions.

* Black Holes: Their properties, formation, and effects on the universe.

* Cosmic Background Radiation: The remnant radiation from the Big Bang.

* Dark Matter and Dark Energy: Their nature and influence on the universe.

Astronomy uses a wide range of tools and techniques, including telescopes, spacecraft, and computer simulations, to understand the universe.