A History of The Constellations

FAS Astronomers Blog, Volume 33, Number 2.

As we look up at the night sky, we see patterns of stars. For many of us these patterns are familiar, and most were identified by the ancients a few thousand years ago. We recognize the constellations and asterisms such as Orion, The Big and Small Dippers, Scorpius, The Summer Triangle, and many more. 

According to the International Astronomical Union there are 88 official constellations. The boarders of these constellations divide the entire sky into eighty-eight segments. Everything we see falls into a specific segment and is associated with that constellation. The artwork and stick figures for the constellations, however, are a bit more arbitrary. Some are drawn several different ways. And for others, we often wonder … How did they come up with that? 

Asterisms are also up to the observer. These are unofficial star patterns that typically have a name and are groups of stars we recognize. Although we are often familiar with them, they are not official constellations. The best-known asterism is The Big Dipper. However, this is a name given to it by those of us in the states. In England it is known as The Plow.

Throughout this article you will see links and pronunciations from “The Constellations.” by The International Astronomical Union.

The First 48 (Constellations not States)

Most of the descriptions of what we see in the night sky come from western culture. Many of the constellations were first identified by the Greeks and Babylonians and are associated with animals and the mythology of the times. A “formal” list of 48 constellations was handed down to us after first being published in the year 150 CE by Claudius Ptolemy in The Almagest. 

Many of these constellations represented mythological figures or stories (21): Andromeda (The Chained Maiden), Aquarius (The Water Bearer), Argo Navis (The Ship of the Argonauts), Auriga (The Charioteer), Boötes (The Herdsman), Capricornus (The Sea Goat), Cassiopeia (The Seated Queen), Centaurus (The Centaur), Cepheus (The King), Cetus (The Sea Monster), Draco (The Dragon), Gemini (The Twins), Hercules(Hercules), Hydra (The Female Water Snake), Ophiuchus (The Serpent Bearer / OFF-ee-YOO-kus, OAF-ee-YOO-kus), Orion (The Hunter), Pegasus (The Winged Horse), Perseus (The Hero), Sagittarius (The Archer / SAJ-ih-TARE-ee-us), Serpens (The Serpent), and Virgo (The Maiden).

Others were simply animals (18): Aires (The Ram), Aquila (The Eagle), Cancer (The Crab), Canis Major (The Great Dog), Canis Minor (The Lesser Dog), Corvus (The Crow), Cygnus (The Swan), Delphinus (The Dolphin), Equuleus (The Little Horse), Leo (The Lion), Lepus (The Hare), Lupus (The Wolf), Pisces (The Fishes), Pisces Austrinus (The Southern Fishes), Scorpius (The Scorpion), Taurus (The Bull), Ursa Major (The Great Bear), and Ursa Minor (The Lesser Bear).

A few represented objects (9): Ara (The Alter),  Corona Australis (The Southern Crown), Corona Borealis (The Northern Crown), Crater (The Cup), Eridanus (The River / ih-RID-un-us), Libra (The Scales), Lyra (The Harp), Sagitta (The Arrow / suh-JIT-uh), and Triangulum (The Triangle / try-ANG-gyuh-lum).

Ptolemy’s list did include several constellations that are viewable primarily from the Southern Hemisphere. These included: Corona Australis (The Southern Crown), Pisces Austrinus (The Southern Fish), and Centaurus (The Centaur). He also listed Crux (The Southern Cross) but included it as an asterism within the constellation Centaurus. 

The New Constellations

Early on, in 1536, the constellations of Antinous (Anti-no-us) and Coma Berenices (Berenice’s Hair / COE-muh BER-uh-NICE-eez) appeared on globes by Caspar Vopel and later by Gerardus Mercator (of the Mercator map projection fame – see Mapping The World). They both were also referenced by Tyco Brahe in his 1602 star catalog. These two constellations were originally considered to be asterisms and included by Ptolemy within other constellations. Antinous was located between Aquila (The Eagle) and Capricornus (The Sea Goat). It has disappeared from our modern list. On the other hand, Coma Berenices is found off the end of  Leo’s tail. Ptolemy considered it to be the tuft at the end of the lion’s tail. Named after the hair of Egyptian Queen Berenices II, Coma Berenices remains with us today. 

As European explorers ventured out into the world and crossed the equator into the Southern Hemisphere, they found stars and patterns of stars that they were not familiar with and were not included in the original 48. Astronomers being the creative group they are, started to suggest new shapes and patterns. Many of these covered the previously unexplored southern sky near the southern pole. Of course, although this part of the sky was unexplored by the Europeans, the southern sky was well known for centuries to the natives of the southern hemisphere. 

Navigating the oceans, and in particular, the mostly uncharted oceans of the south Pacific, required reliable star charts. It was the Portuguese who first ventured south well below the equator. However, they were very secretive with their maps and chart. So, if they did chart the southern sky, they didn’t publish or release any maps. The Dutch came next. Cartographer Petrus Plancius was one of the first to create maps of the unobserved sky around the southern pole. 

In 1582, Plancius identified a new constellation Columba (The Dove), which is with us today and made it into some of the globes and charts of the early 17^th century. 

Shortly later, near the end of the 16^th century, Plancius provided Pieter Dirkszoon Keyser with the training and sea charts necessary to chart the night sky. Keyser sailed south to Madagascar in 1595. There he observed the night sky and identified (created?) twelve new constellations – all of which are still with us today. Unfortunately, Keyser died before returning to Europe, however, his observations (and new constellations) were communicated to Plancius. He, in turn, provided them to fellow cartographer Joducus Hondius, who produced a globe with the twelve constellations in 1598. Iodocus Holland followed the next year with another globe also including the new constellations. 

Traveling with Keyser was Frederick de Houtmann, who also charted the sky and observed the same star patterns. De Houtmann undertook a second voyage down toward the “East Indies” in 1598. Upon his return, in 1603. he published a dictionary of the native language (Malay) and included his star charts along with the new constellations at the end. 

There has been some debate over who was actually responsible for these new constellations. Was it Keyser or de Houtmann – or possibly Plancius? Today, all are given some credit. 

For the record, the new constellations were, Apus (The Bird of Paradise), Chamaeleon (The Chameleon), Dorado (The Swordfish), Grus (The Crain), Hydrus (The Male Water Snake), Indus (The Indian), Musca (The Fly), Pavo (The Peacock), Phoenix (The Phoenix), Triangulum Australe (The Southern Triangle), Tucana (The Toucan), and Volans (The Flying Fish).

Several years later, in 1612, Placius produced another globe with an additional eight constellations. Most have disappeared, however two remain with us today, Monoceros (The Unicorn / muh-NAH-ser-us), and Camelopardalis(The Giraffe / cuh-MEL-oh- PAR-duh-liss).

The new constellations caught on in 1603 with the publication of the German Johann Bayer’s popular catalog (Uranometria Omnium Asterismorum). He included them, in addition to Ptolemy’s 48 constellations, in chart 49, which focused on the stars near the southern pole. Bayer also included two summary charts (51 and 52), one each for the Northern and Southern Hemisphere respectively. 

There have been several stories about the creation of Crux (The Southern Cross) as a distinct constellation rather than representing it as an asterism within Centaurus. According to Ian Ridpath, Frederick de Hautman first referred to it this way in 1603. 

A catalog, ‍‍Usus ‍Astronomicus ‍Planisphaerii ‍Stellati, was published in 1624 by Jacob Bartsch including Crux as a distinct constellation. He also referenced Monoceros (The Unicorn / muh-NAH-ser-us), and Camelopardalis (The Giraffe / cuh-MEL-oh- PAR-duh-liss) previously proposed by Placius. Isaac Habrcht published a similar catalog, Planiglobius coeleste et Terrestre, in 1628. 

Johannes Hevelius came along next and added several new constellations in the latter quarter of the 17^th century. He and his wife, Elisabeth, built a state of the art (for the time) observatory called “Stellaburg,” in Gdansk. Regrettably, it burned down in 1679, and in the process, destroyed most of Hevelius’ equipment, books, and manuscripts. He died in 1685, but his wife published his extensive star catalog (Firmamentum Sobiescianum sive Uranographia) in 1690. Included in it were his new constellations. 

The 1690 publication added the constellation Sextans (The Sextant) after the instrument Hevelius used to chart the night sky. In addition, six others were included and are still with us today. Hevelius did exclude a few of Ptolemy’s constellations because they were too far south to be observed from his observatory: Ara, Centaurus, Corona Australis, Lupus, and Piscis Austrinus.

The six new constellations are: Canes Venatici (The Hunting Dogs / {CANE-eez or CAN-eez} ve-NAT-iss-eye), Lacerta (The Lizard / luh-SER-tuh), Leo Minor (The Lesser Lion), Lynx (The Lynx), Scutum (The Shield), and Vulpecula (The Fox / vul-PECK-yuh-luh). 

In 1751, Nicolas-Louis de Lacaille traveled below the equator to the southern tip of South Africa. For the next few years, he cataloged the southern sky and identified 14 new constellations. De Lacaille had had a great passion for science and the various instruments used in scientific endeavors, and, as such, named several of these new constellations after scientific equipment. These fourteen constellations are still found in today’s sky

They are: Antlia (The Air Pump), Caelum (The Engraving Tool), Circinus (The Drawing Compass), Fornax(The Furnace), Horologium (The Clock), Mensa (The Table Mountain), Microscopium (The Microscope), Norma (The Carpenter’s Square), Octans (The Octant), Pictor (The Painter’s Easel), Pyxis (The Mariner Compass), Reticulum (The Reticle), Sculptor (The Sculptor), and Telescopium (The Telescope). 

De Lacaille, in 1750, also divided Argo Navis (The Ship of the Argonauts), into three smaller ones representing parts of the ship, Carina (The Keel), Puppis (The Stern), and Vela (The Sails).

Not everyone was thrilled with de Lacaille’s choices. According to Joe Rao of space.com, Heber Curtis, then director of the Allegheny Observatory and one of the participants in The Great Debate, commented “It looks like somebody’s attic!”

All these new constellations, and a few others that are now obsolete, made it into one of the more popular star catalogs of the time, Uranographia sive Astrorum Descriptio published by Johann Elert Bode in 1801. 

The 88 Official Constellations

With various astronomers developing their own list of constellations, the sky became somewhat of a patchwork. F. Michael Witkoski described the situation in a 2024 Astronomy Magazine article.

By the latter half of the 19th century, star charts and atlases featured loosely fabricated patchworks of constellations with arbitrary boundaries of varying shapes and sizes. Many included elaborate drawings of figures overlaying the stars, and different sources gave different delineations. The growing complexity of astronomy, however, demanded more accuracy, necessitating the refinement of such vague impressions of our sky.

F. Michael Witkoski. “Where did the constellations come from?” Astronomy Magazine. August 20, 2024. Updated August 21, 2024.

Finally, in 1922, the International Astronomical Union stepped in, and, at their first meeting, officially designated 88 constellations. In 1930, they went further and established official boundaries around each of them so that everything in the sky can be associated with one and only one constellation. 

Twelve of the constellations have a special meaning. For some they are the constellations of the zodiac. For others, they are the constellations of the ecliptic and define the path the Sun appears to go through over the course of a year. For more on this, see Astrology to Astronomy.

Not all constellations are visible year-round. For those of us in the Northern Hemisphere, constellations toward the southern horizon follow a seasonal pattern with a different group appearing after sunset for each of the four seasons. Those to the northern horizon follow a circumpolar path as they appear to circle the North Star. For information on the specific constellations visible by season, see Quick Introduction to the Night Sky and The Stars & Constellations. 

In Summary

Of course, for many of us who live in the Northern Hemisphere, the constellations of the Southern Hemisphere are out of reach. I’ll address these in a future article, but, for now, a few links are provided below to get you started. 

For an in-depth discussion of the constellations and their history, and a source for this article, see Ian Ridpath’s Star Tales. Myths, legends, and history of the constellations and the many links that are found online.

Astronomer	Publication	Date(s)	Constellations
Claudius Ptolemy	The Almagest	150 CE	47 ancient constellations
Casper Vopel & Gerardus Mercator		1536 & later	Coma Berenices
Petrus Plancius		1582	Columba
Petrus Plancius & Pieter Dirkszoon Keyser		1589	12 New Constellations
Frederick de Houtmann		1603	Same 12 as above
Johann Bayer	Uranometria Omnium Asterismorum	1603	Same 12 as above & Crux
Petrus Plancius		1612	Monoceros & Camelopardalis
Jacob Bartsch	Usus Astronomicus Planisphaerii Stellati	1624	Crux, Monoceros & Camelopardalis
Johannes Hevelius	Firmamentum Sobiescianum sive Uranographia	1690	Sexton & six new constellations
Nicolas-Louis de Lacaille		1750	Argo Navis -> Carina, Puppis, and Vela
Nicolas-Louis de Lacaille		1751	14 Scientific Instruments
Elert Bode	Uranographia sive Astrorum Descriptio	1801	Most modern constellations