Astronomy is the study of the planets and the stars, and in Hogwarts, classes take place at the top of the highest tower of the castle at midnight. Equipment used includes telescopes, astrolabes and star charts, all of which assist the astronomer in charting the movements of planets or identifying stars and constellations.

In Hogwarts, this class is mandatory for the first five years of study, after which it can be taken as an elective until the seventh year.

First year: Students are introduced to the basics of astronomy. They are taught the names of each of the planets in the solar system, their distinguishing characteristics and their positions in the night sky. In addition, they are lectured on the properties of stars, the names of surrounding galaxies and constellations. They are also taught how to properly care for and adjust the instruments used in observation.

Second year: Coursework for the second year of astronomy includes charting the movements of planets, predicting eclipses and researching the properties of nebulae, asteroids, comets and meteors.

Third year: Work continues in charting the movements of plantets and their moons, along with asteroids and meteors. Some history is also covered, namely the biographies of famous astronomers and mythology relating to planetary names.

Fourth year: Students continue to learn to track the movements of the planets and begin to study the effects that certain alignments have upon the casting of spells and brewing potions.

Fifth year: A great deal of the coursework involves filling out star charts and the usage of telescopes to track the courses of planets. Constellations are also researched.

For the OWLs: Students are expected to fill out star charts and with the usage of school telescopes, correctly identify all of the stars and planets visible in the night skies.

Sixth year: Those who continue into the advanced studies of Astronomy begin to study the more indepth theories that star alignments have upon spellcasting and potion-brewing. Independent study is encouraged, and coursework also focuses on the search for new stars.

Seventh year: Independent study becomes more the theme for seventh-year students, and more time with the telescopes is devoted to the search for new and very distant stars. Coursework from the previous years is also reviewed for the NEWTs.

For the NEWTs: Students are expected to have prepared a thesis paper on the topic of their choice, which has been the focus of their independent studies. They are also expected to be able to fill out star charts, identify planets and stars and show understanding of studies from previous years.