Uranometria

Uranometria - Body

star atlas

Mapping the Night Sky

An illustration of several human figures surrounding text. Below the text is a small illustration of a cityscape. Text reads: IOANNIS BAYERI RHAINANI 1.c. VRANOMETRIA, OMNIUM ASTERISMORUM CONTINENS SCHEMATA. NOVA METHODO DELINE ATA AEREIS AMINIS EXPRESSA. Text on one side of the cityscape reads: ATLANTI VETVSTISS ASTRONOM MAGISTRO and on the other side reads: HERCVLI VETVSTISS ASTRONOM DISCIPVLO

Johann Bayer (1572-1625) was not a trained scientist. He worked as a lawyer in Augsburg, Germany. He had an interest in astronomy and taught himself how to observe, research, and document the night sky. In 1603, he published his star atlas titled Uranometria. Uranometria is book containing 51 constellation maps of the night sky. The maps in Bayer’s star atlas were the most accurate and artistic ever produced at that time.

Because of its accuracy and artistry, Uranometria was very popular. For 200 years after its publication, the atlas was reprinted almost a dozen times. It inspired several other astronomers to create similar works. Bayer’s work continues to influence the way we understand and discuss the night sky. Bayer’s star atlas started the “golden age” of constellation maps.

Title page in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Features of a Constellation Map

Star atlases, maps of the night sky, have been around for thousands of years. Between 1600-1800, it was very popular to create star atlases, and many astronomers, both professional and amateur, created their own maps of the night sky. These atlases depicted constellations and provided readers with information about celestial bodies, including their location and brightness. It is easier for people to identify groups of stars in the night sky than a single star, so constellations can be a helpful organizational tool for astronomers and navigators.

Almost every detail in Bayer's constellation maps conveys information about Bayer’s thinking. In Uranometria, Bayer adopted, adapted, and developed several features of constellation maps. Use the interactive image below to explore these features.

Star Atlas Hercules

target icon target icon target icon target icon target icon Printed chart with stars of different sizes and an illustration of a person wearing a lion skin and holding a club in one hand and a plant sprig in the other

Hercules (flipped 180°) in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

  • Classical Greek Traditions In the first century CE, the Greek astronomer Ptolemy identified 48 constellations in the night sky. Almost 2000 years later, astronomers like Bayer organized their atlases using the constellations provided by Ptolemy. Which of Ptolemy’s constellations have you heard of? What do you know about them?

    • Ursa Minor
    • Ursa Major
    • Draco
    • Cepheus
    • Boötes
    • Corona Borealis
    • Hercules
    • Lyra
    • Cygnus
    • Cassiopeia
    • Perseus
    • Auriga
    • Ophiuchus
    • Serpens
    • Sagitta
    • Aquila
    • Delphinus
    • Equuleus
    • Pegasus
    • Andromeda
    • Triangulum
    • Aries
    • Taurus
    • Gemini
    • Cancer
    • Leo
    • Virgo
    • Libra
    • Scorpius
    • Sagittarius
    • Capricornus
    • Aquarius
    • Pisces
    • Cetus
    • Orion
    • Eridanus
    • Lepus
    • Canis Major
    • Canis Minor
    • Argo
    • Hydra
    • Crater
    • Corvus
    • Centaurus
    • Lupus
    • Ara
    • Corona Australis
    • Piscis Austrinus

  • Myths and Stories Each constellation is a group of stars. These stars can be millions of light years away from each other, but from Earth they appear close together. Early astronomers looked at the sky and used their imaginations to assign myths, stories, and objects to different groups of stars. These familiar myths, stories, and objects helped people remember and locate the constellations. The stars in the constellation only provide a few points on the figure, so each astronomer artist had a lot of creative freedom in how they depicted the figures. Bayer’s artistic constellation maps give additional visual representation to the constellations. The constellation on this map is Hercules, a Greek demigod known for his superhuman strength and epic adventures that have inspired artworks, books, and theater for thousands of years.

  • Coordinate System the purpose of a map is to help people identify the locations and relationships between different objects in space. Constellation maps include a coordinate system that readers can use to understand the positions of different stars. Bayer included a grid on the edges of each constellation map. Readers can use a straightedge (like a ruler) to identify each star’s position to a fraction of a degree. Bayer was the first person to create such a precise grid, and his constellation maps were much more accurate than previous works.

  • Classifying the Stars Bayer developed a method of classifying and naming stars that is still used today. In each constellation, he assigned every star a Greek letter. He started with the brightest star, assigning it “alpha” (the first letter of the Greek alphabet). The second brightest star was assigned “beta” (the second letter of the Greek alphabet) and so on. If a constellation had more stars than the Greek alphabet had letters (24), Bayer continued his list with the Latin alphabet.

  • Star Catalog This interactive image only shows one side of the constellation map. On the back of each map, Bayer includes the Ptolemaic name for each constellation and a discussion of the different names of the constellation. He also includes a list of all the stars with information about their position within the constellation, their magnitude (brightness) and their astrological association. In his star catalog on the back of each map, Bayer provided two identifications for each star: his Greek (or Latin) letter identifier and Ptolemy’s number identifier. His new identification system provided more information to the reader, but readers were more familiar with Ptolemy’s system. Bayer helped his readers by including both.

Bayer’s Influences

Bayer’s star atlas started the “golden age” of constellation maps, but printed star maps existed prior to this period. Two likely influences for Bayer’s work are the illustrations of Jacques de Gheyn II, and On Fixed Stars by Alessandro Piccolomini.

The illustrations created by de Gheyn II in 1600 are artistic but not accurate. His work includes highly artistic representations of the constellations. The stars are inaccurately placed, and there is no coordinate system showing the stars’ positions in the sky.

Piccolomini’s On the Fixed Stars (published 1540) is accurate but not artistic. It includes a star catalog with mythological descriptions of 47 of Ptolemy’s 48 constellations. Piccolomini was the first astronomer to show the relative brightness of stars in his atlas; he lists the brightest stars with Latin letters. Piccolomini included a scale of degrees to help readers determine the size of the constellation, but he did not include a coordinate system. This meant readers could not locate individual stars. Each map included an accurate representation of the constellation’s star pattern as seen from Earth. None of these maps included artwork for the constellations.

Use the image slider below to compare and contrast de Gheyn’s II, Piccolomini’s, and Bayer’s versions of the constellation Orion.

Illustration of a person in draped clothing holding one arm out with a lion pelt on it and the other arm pulled back holding a rod

Orion in Arataea sive signa coelestia, Jacques de Gheyn II, 1600-1621, engraving. The British Museum. 1952,0705.1.63.

Printed chart with stars of different sizes. Many stars have a Latin letter next to them.

Orion in De le stelle fisse (On the fixed stars), Alessandro Piccolomini, printed book, 1540. The Huntington Library, Art Museum, and Botanical Gardens. 482266.

Printed chart with stars of different sizes and an illustration of a person in loose robe clothing holding a lion skin on one arm and a club in the other hand.

Orion in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Northern Hemisphere

In the first century CE, the Greek astronomer Ptolemy identified 48 constellations in the night sky. Bayer created 49 constellation maps, 48 of which are of Ptolemy’s constellations. Use the questions and prompts below to analyze one (or more) of Bayer’s northern hemisphere constellation maps.

Printed chart with stars of different sizes and an illustration of a small bear with a large beaver-like tail

Ursa Minor in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a large bear with a small beaver-like tail

Ursa Major in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a serpent-like creature with a small mane

Draco in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a person in an active pose wearing ancient Greek-style armor

Cepheus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a person with a scythe beside a bundle of grain

Boötes in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of wreath of leaves

Corona in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a person wearing a lion skin and holding a club in one hand and a plant sprig in the other

Hercules in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a bird of prey with a harp-like instrument in front of it

Lyra in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a swan viewed from the top

Cygnus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a person in draped cloth clothing and a helmet holding a shield and a sword

Perseus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a person in draped cloth clothing and a hood carrying two small animals on their back. The person is holding a streamer.

Auriga in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a snake stretched out and gripped by a person wearing only a sheet loosely draped around their torso and buttocks

Serpentarius in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a snake with defined scales stretched across the page

Serpens in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of an arrow

Sagitta in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a large bird carrying a naked human

Aquila in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a sea creature with a finned crest and no visible side fins

Delphinus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of an upside-down horse head emerging from clouds

Equus Minor in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of an upside-down winged horse with the front half of its body emerging from a cloud

Pegasus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a person with long hair, bare breasts, and a cloth draped around their waist. The person's wrists are in metal cuffs and chained to their torso.

Andromeda in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a hollow right triangle

Triangulum in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a ram

Aries in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of the head of a bull

Taurus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of two people who look the same embracing. One holds an arrow and the other holds a hand scythe.

Gemini in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a crab

Cancer in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a lion with a mane

Leo in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a person with curly hair, a draped dress, and wings. The person is holding a plant sprig

Virgo in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a set of scales

Libra in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a scorpion

Scorpio in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a winged centaur holding a bow and arrow

Sagittarius in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a creature with the head of a horned goat and the finned tail of a sea creature.

Capricornus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a person with a thin piece of cloth draped around them as they spill liquid from a large vase

Aquarius in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of two fish swimming in different directions

Pisces in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a sea serpent-like creature

Cetus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a person in loose robe clothing holding a lion skin on one arm and a club in the other hand.

Orion in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a river with grasses growing on the banks

Eriadnus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a rabbit

Lepus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a small dog

Canis Minor in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a large and decorated ship with four people on board. The ship is passing a large rock formation

Nauis (Argo) in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a centaur battling a dog-like creature

Centaurus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a vase with two handles and pattern decoration

Crater in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a crow-like bird

Corvus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a serpent with an open mouth and extended tongue

Hydra in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a wolf

Lupus in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of an hourglass shape with flames coming out the bottom and three foot-like objects coming out the top

Ara in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a wreath of leaves

Corona Meridionalis in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Printed chart with stars of different sizes and an illustration of a sea creature with a crested fin, finned tail, no side fins, and sharp teeth

Piscis Notius in Uranometria, Johannes Bayer, 1603, printed book. The Huntington Library, Art Museum, and Botanical Gardens. 482143.

Choose one of the above constellation maps. Allow the prompts and questions below to guide your observation. Once you’re done, you can choose a second constellation map and repeat the process. Compare your responses for the two constellation maps. You can also compare your responses to those of a peer.

Questions & Prompts

  • Look closely at this constellation map. What do you notice first? What do you notice after looking for a full minute?

  • How did Bayer use observations of the natural world when creating this work?

  • How did Bayer use his imagination and creativity when creating this work?

  • Does this work remind you of anything? What? Why?

  • What do you think Bayer was trying to communicate? What do you see in the object that makes you think that?

  • How does Bayer’s culture affect his understanding of the stars?

  • What do you know about the myth, story, animal, or object in your chosen constellation? Does this work tell a story? If so, what story?

  • Many of the constellations feature popular stories, people, and animals from Ancient Greece. If you were naming constellations today, what stories, people, and animals would you choose for the names? Why?

Southern Hemisphere

Bayer’s atlas includes 49 constellation maps, and 48 of these maps depict constellations in the northern hemisphere. The 49th map is special; it is the first European star atlas depicting the constellations of the southern hemisphere.

In addition to being the “golden age” of star atlases, the 1600s-1800s was a period of European colonialism and imperialism. Europeans referred to this period as the Age of Exploration. At a time when they were traveling the world by ship, it was essential that they knew how to navigate the open ocean. One of the few reliable methods for figuring out their exact location depended on having accurate star maps of these unfamiliar skies.

Bayer was the first to try to create an accurate star map of the southern hemisphere. He based his 49th map on observations made by three European explorers. He used their descriptions of 12 new constellations to guide his illustrations. Use the questions and prompts below to analyze of Bayer’s 49th map.

Expand image Printed chart with stars of different sizes and illustrations of multiple figures

Chart of the South Polar Sky in Uranometria, Johannes Bayer, 1603, printed book. Mount Wilson and Las Campanas Observatories. The Huntington Library, Art Museum, and Botanical Gardens. 487000:0362

Questions & Prompts

  • Bayer included the names of the constellations on the map. Can you identify the names of any of the constellations? Are any of them familiar to you?

  • How is this map different than the 48 northern hemisphere maps? How is it similar?

  • What information do you think Bayer learned from the European explorers’ descriptions?

  • What information do you think Bayer didn’t know? What questions might he have had?

References and Resources

Boston Athenæum. 2014. “Uranometria.” Accessed May 3, 2022. https://www.bostonathenaeum.org/about/publications/selections-acquired-tastes/uranometria.

Brashear, Ronald, Daniel Lewis, and Owen Gingerich. 2001. Star Struck: One Thousand Years of the Art and Science of Astronomy. San Marino, CA: The Huntington Library in association with the University of Washington Press, Seattle.

Encyclopaedia Britannica.  n.d. “Johann Bayer: German Astronomer.” Accessed May 3, 2022. https://www.britannica.com/biography/Johann-Bayer.

Kanas, Nick. 2019. Star Maps: History, Artistry, and Cartography. Switzerland: Springer Nature Switzerland.

Warner, Deborah Jean. 1979. The Sky Explored: Celestial Cartography, 1500-1800. New York: A. R. Liss.

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