Lecture Notes: Pictures in the Sky - The Origin and History of the Constellations

Introduction

• Speaker: Ian Ridpath
• Topic: History and origin of constellations
• Books by Speaker: "Star Tales", Oxford Dictionary of Astronomy

Overview of Constellations

• Constellations are human inventions, not eternal fixtures in the sky
• Serve as one of the earliest attempts to impose order on the universe
• Story traces back over 3,000 years, involving a journey around the Mediterranean
• Currently, there are 88 recognized constellations
• Names and boundaries are fixed by international agreement

Historical Storytelling and Constellations

• Early constellations likely began as stories around communal fires
• Stories of gods, mythical heroes, and beasts
• Stars used to illustrate tales
• Original constellations were allegorical, not literal representations

Cultural Perspectives

• The Greeks are credited with many constellations, but other cultures like the Chinese had their own versions
• Chinese constellations vastly different and often more numerous

Ancient Greek Contributions

• First mentions in literature: Homer and Hesiod (~700 BC)
• Eudoxus and Aratus contributed early constellation catalogues
• The Farnese Atlas is the earliest known celestial globe

Ptolemy's Almagest

• Comprehensive description of constellations in 2nd century AD
• Catalogued approximately 1,000 stars in 48 constellations

Arabic Influence

• Arab scholars preserved Greek works and expanded them
• Al-Sufi's "The Book of the Fixed Stars" included Islamic illustrations
• Transmission of names and ideas through Spain into Western Europe

Star Naming

• Many star names are of Arabic origin, often from astrolabes
• Examples: Vega, Altair, Sirius

Age of Exploration and Printing

• New constellations introduced during explorations
• Significant contributors: Petrus Plansius, Johann Bayer, Johann Hevelius
• Introduction of Bayer letters for star cataloging

17th to 18th Century Developments

• New constellations added
• Hevelius' contributions included constellations like Lynx, Scutum
• De la Caille introduced several constellations named after scientific instruments

Modern Standardization

• International Astronomical Union (IAU) standardized constellations in 1922
• Fixed the number at 88 constellations
• Boundaries drawn by Eugene Delporte in 1930

Future of Constellations

• Stars are moving; constellations will change shape over time
• Proper motions alter constellations over tens of thousands of years

Final Thoughts

• Constellations connect us to early human civilizations
• Ian Ridpath’s website offers more on constellations and obsolete ones

• Additional Resources: Ian Ridpath's website for further reading on constellation stories and obsolete constellations.