Here's a breakdown of what astronomy encompasses:

* Stars: Astronomy investigates the formation, evolution, properties, and life cycle of stars. This includes their composition, temperature, brightness, and how they generate energy.

* Planets: Astronomy studies the planets in our solar system and beyond, including their orbits, atmospheres, geology, and potential for life.

* Other celestial objects: Astronomy also covers the study of galaxies, nebulae, black holes, comets, asteroids, and more.

* Cosmology: A branch of astronomy focuses on the origin, structure, and evolution of the universe as a whole.

Essentially, astronomy is the scientific study of everything in space!