Astronomy

"Harry, yours is okay except for this bit at the end, I think you must have misheard Professor Sinistra. Europa's covered in ice, not mice."

- Hermione Granger to Harry Potter in 1995

Astronomy is a subject taught at Hogwarts School of Witchcraft and Wizardry. It is a required subject for first to fifth years, but can be dropped in the sixth year. Aurora Sinistra was the Astronomy teacher at Hogwarts.

Astronomy classes take place in the top-most level of the Astronomy Tower, the tallest tower in Hogwarts Castle, and include sky observation sessions with telescopes (each student has to buy one of his/her own).

Astronomy is one of the only fields of study at Hogwarts which has a direct equivalent in the Muggle world. Known student activities include learning the names of stars, constellations and planets, as well as their location and movements, and describing the environments of planets and moons.

Wisearcre's Wizarding Equipment in Diagon Alley sells telescopes and other equipment needed for Astronomy.

Lesson times

 * First year
 * Wednesday (12:00 am)
 * Fifth year
 * Wednesday (evening)

First year
During the first year of studies at Hogwarts, students must study the night skies through their telescopes every Wednesday at midnight and learn the different names of the stars and the movements of the planets. Towards the end of the year, Hermione was quizzing Ron on Astronomy. Their studying included using a map of Jupiter. It was noted that Harry tried to learn the names of Jupiters Moons in his fifth year of study at Hogwarts.

Third Year
Although Astronomy lessons were not shown during his third year, one of the homework assignments included drawing a star chart which probably means they studied stars that year.

Fifth Year
During the fifth year of studies at Hogwarts, students must study Jupiter's moons, and write an essay containing facts such as Europa being covered by ice and Io having many volcanoes. For the Astronomy O.W.L. exam in their fifth year, each student has to "fill in a blank star chart" based on a few hours of observing the night sky. Coursework during this year was intensive enough that some students had to organize a meeting to help each other get through it.

Harry Potter was taking his Astronomy O.W.L. in 1996 when Rubeus Hagrid was confronted by Professor Umbridge and a team of Aurors in what was an attempted sacking, which was also the night that Minerva McGonagall took "no less than four Stunners to the chest".

Known O.W.L.s

 * Aurora Sinistra
 * Barty Crouch Jr
 * Bill Weasley
 * Percy Weasley
 * Hermione Granger
 * Harry Potter
 * Ron Weasley

Behind the scenes

 * During the O.W.L. exam, Harry focuses his telescope upon Venus at midnight. However, Venus' orbit is closer to the Sun and when it is midnight at a location, that part of the Earth is approximately facing completely away from the Sun. Given these two facts, it is highly unlikely that Harry would have been able to see Venus regardless of Britain's high latitude and the proximity to the Summer Solstice due to line of sight issues, but the telescope may have been magical.
 * In the films, the Astronomy class is never seen or directly mentioned, and Professor Sinistra only appears as an unidentified background extra.
 * From the fact that it's common knowledge among Wizards that Europa is icy and Io has volcanoes, it seems that, despite the separation of Wizarding and Muggle cultures (and the Wizarding ignorance of other scientific concepts such as electricity), Muggle science is well-known to Wizard astronomers. Just how far Wizarding knowledge of modern astronomy goes, though, is unknown. However, it is quite possible that the wizarding world has other means of conducting these studies without the use of muggle technology, as Professor Trelawney possessed a globe of the solar system that accurately depicts all the planets (including Pluto) and their moons. Furthermore, Harry Potter found a moving globe of the galaxy in Diagon Alley when he was staying at the Leaky Cauldron during the summer before his third year. This far surpasses the current state of muggle knowledge, let alone what it was in the early 1990s.

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Chamber of Secrets
 * Harry Potter and the Prisoner of Azkaban
 * Harry Potter and the Prisoner of Azkaban (film)
 * Harry Potter and the Goblet of Fire
 * Harry Potter and the Order of the Phoenix
 * Harry Potter and the Order of the Phoenix (video game)
 * Harry Potter and the Half-Blood Prince
 * Harry Potter and the Half-Blood Prince (film)
 * LEGO Harry Potter: Building the Magical World
 * LEGO Harry Potter: Characters of the Magical World
 * Pottermore