Constellations

• Type: Astronomical phenomena; subject of Astronomy; tool for Divination; naming tradition
• Owners: Not applicable
• Maker: Not applicable

Constellations are groups of stars that form recognisable patterns in the night sky as viewed from Earth. In the wizarding world, as in the Muggle world, these patterns are given names and are charted for use in Astronomy. The study of constellations involves learning their names, the names of the individual stars within them, and their movements across the celestial sphere. Students at Hogwarts are required to learn and identify various constellations. During his O.W.L. exam, Harry Potter is tasked with filling in a blank star chart, which involves correctly placing constellations like Orion, which he had previously observed from the Astronomy Tower.

While constellations are natural phenomena, their observation and interpretation are key components of magical disciplines.

• Astronomy: The primary use of constellations is in the field of Astronomy, a core subject at Hogwarts taught by Professor Aurora Sinistra. Students learn to identify constellations and track the movements of celestial bodies. This knowledge is considered a fundamental part of a magical education, tested via a practical and theoretical O.W.L. exam in the fifth year.
• Divination: The positions and alignments of constellations are crucial for astrological Divination. Professor Sybill Trelawney teaches her students to interpret star charts to make predictions.
• Centaur Divination: Centaurs are master stargazers who practice a form of Divination they consider far superior to human methods. They believe the movements of the planets and stars foretell major world events. Firenze, after being banished from his herd, teaches Divination at Hogwarts, explaining that the burning of the stars can reveal futures. He notes that the unusual brightness of Mars during Harry's fifth year was a clear omen of a coming war.

The study of constellations is an ancient practice in the wizarding world, particularly among Centaurs, who have been “unraveling the mysteries of the planets” for centuries. A significant cultural use of constellation and star names is the naming tradition within the noble House of Black. For generations, this ancient and powerful pure-blood family has named its members after celestial bodies, reflecting their proud and lofty self-image. Notable examples include:

• Sirius Black (named after the brightest star in the Canis Major constellation, known as the “Dog Star”)
• Regulus Arcturus Black (named after the brightest star in the Leo constellation and the brightest star in the Boötes constellation, respectively)
• Bellatrix Lestrange (née Black, named after the third-brightest star in the Orion constellation)
• Andromeda Tonks (née Black, named after the Andromeda constellation)
• Narcissa Malfoy (née Black, whose name origin is from a figure in Greek mythology associated with a flower, a break in tradition, though her son Draco Malfoy is named after the Draco constellation)
• Orion Black (named after the Orion constellation)
• Cygnus Black (named after the Cygnus constellation)

Constellations serve multiple roles throughout the series, functioning as an element of world-building, characterisation, and foreshadowing.

• Education and Setting: The study of constellations establishes Astronomy as a legitimate academic subject at Hogwarts, grounding the magical world with real-world science. The Astronomy Tower, where students conduct their observations, becomes a pivotal location, most notably as the site of Albus Dumbledore's death.
• Characterisation: The House of Black's naming tradition provides instant insight into the family's heritage and values. The name Sirius Black is a direct clue to his Animagus form, a large black dog, as his namesake is the “Dog Star.”
• Plot and Foreshadowing: Firenze's teachings connect the movement of the stars directly to the unfolding Second Wizarding War. His lessons provide a broader, more cosmic perspective on the conflict, contrasting with the often mundane and inaccurate predictions of Professor Trelawney. This highlights the Centaurs' wisdom and their serious approach to reading the future in the heavens.

• J.K. Rowling has confirmed that the naming convention for the House of Black was a deliberate choice to convey their sense of being “a very old, aristocratic family” who believe themselves to be “practically royalty.” (J.K. Rowling interview)
• In the film adaptation of Harry Potter and the Order of the Phoenix, the Black Family Tapestry in Number Twelve, Grimmauld Place is shown with constellations artistically woven around the names of the family members, visually reinforcing this naming theme. (film)