Because the human brain has a powerful urge to recognize pattern, we see patterns in the night sky, patterns like the Big Dipper. These patterns are called “asterisms.” Most asterisms are due to our point of view, and are not the result of a real, physical grouping of stars. An asterism may include small nearby stars and giant but distant ones.

Names of the constellations

Many cultures have had named constellations: the Chinese, for example. But because modern astronomy arose out of the Western tradition, the names now used internationally have Western roots. A number of constellations are mentioned in Homer (9th century bce), and Greek references are frequent by the 6th century bce, but the names appear to have come from even older cultures along the Euphrates River, possibly by way of the Phoenicians.

Drawing on the work of the astronomer Eudoxus, sometime around 270bce a poet named Aratus wrote a long poem called Phenomena, in which he described 44 constellations and told their stories. This work was extremely popular in classical times. No less an author than Cicero translated it into Latin. To this day, most books that tell the stories of the constellations are retellings of Aratus.

Ptolemy listed 48 constellations and their locations in his He Mathematike Syntaxis (2nd century ad). Medieval Europeans knew this work as the Almagest, its translation into Arabic. Most of the constellation names given in the Almagest are still in use.

Astronomers' view of constellations

To the astronomer, a constellation is not an asterism, but a well-defined area on the celestial sphere. So, for example, every constellation that is a part of the zodiac must occupy exactly one-twelfth of the celestial equator, a point recognized by the ancient Greeks. Every point on the celestial sphere must lie in one constellation or another; the entire celestial sphere is tiled with constellations.

As European astronomers began to travel to the Southern Hemisphere, more names were required to cover the part of the celestial sphere that can never be seen from Earth's Northern Hemisphere. The names of twelve of these southern constellations, suggested by Pieter Dirckszoon Keyzer, Amerigo Vespucci, Andrea Corsali and Pedro de Medina, were canonized by their use in 1630 in plate 49 of Johnn Bayer's extremely popular star atlas, Uranometria. By the end of the 17th century, astronomers were inventing new constellations to fill those regions which, because they contained few prominent stars, had never been identified with a particular constellation.

boundary of the constellation Orion

Boundary of the constellation Orion.

Differing definitions of the constellations and the use of curved boundaries (which made it a bit more difficult to determine in which constellation a given location lay) led the International Astronomical Union to standardize the names and the boundaries of the constellations in 1930, making them all run either north-south or east-west, like lines of latitude and longitude on the Earth.²

The names of the constellations are used in naming prominent stars. In a star's name the genitive form of the constellation's name is used, or it is abbreviated. The redrawing of the constellations' boundaries in 1930 resulted in a few stars no longer being in the constellations from which they take their names.

The system of three letter abbreviations for the names of constellations was proposed by Hertzsprung and Russell, and adopted with slight modifications by the First General Assembly of the IAU in 1922.At the same meeting, it was decided that astronomers would use only the Latin form of the names of constellations.

The genitive form and abbreviation are given in the table below. The size is given in square degrees.² In comments, the letter refers to the first record of the name:

Name Genitive Abbr. Meaning of name Size
sq. °
AndromedaAndromedae Andan Ethiopian princess722P
AntliaAntilaeAntair pump239 L, originally Antilia Pneumatica
ApusApodis Apsbird of paradise206B, originally Avis Indica
AquariusAquariiAqr water bearer980P
Aquila AquilaeAqleagle653P
AurigaAurigaeAurcharioteer657 P
BoötesBootisBooherdsman 907P
CaelumCaeliCae chisel125L, originally Caela Sculptoris
CamelopardalisCamelopardalisCamgiraffe 757H
CancerCancriCnc crab506P
Canes VenaticiCanum VenaticorumCVnhunting dogs465H
Canis MajorCanis MajorisCMabig dog 389P
Canis MinorCanis Minoris CMismall dog183P
Capricornus CapricorniCapgoat414P
CarinaCarinaeCarship's keel494 formerly part of Argo Navis
Cassiopeia CassiopeiaeCasan Ethiopian queen598P
CentaurusCentauriCencentaur1,060 P
CepheusCepheiCepking of Ethiopia588P
CetusCeti Cetwhale1,231P
Chamaeleon ChamaeleonisChachameleon132B
CircinusCirciniCircompass93 L
ColumbaColumbaeColdove 270Jacobus Bartschius, 1694, as Columba Noachi (Noah's Dove)
Coma Berenices Comae BerenicesComBernice's hair387 3rd century bce, but not recorded until Tycho Brahe's catalog (1602)
Corona AustrinaCoronae AustrinaeCrAsouthern crown128P. Sometimes called Corona Australis
Corona BorealisCoronae BorealisCrBnorthern crown179P
CorvusCorvi Crvcrow184P
Crater CraterisCrtcup282P
CruxCrucisCrucross68 Augustine Royer, 1679) as Crux Australis, the Southern Cross.
CygnusCygniCyg swan804P
DelphinusDelphini Delporpoise189P
Dorado DoradusDorswordfish179B
EquuleusEquuleiEqulittle horse72 P
EridanusEridaniErithe River Eridanus1,138P
Fornax FornacisForfurnace398L, originally Fornax Chemica
GeminiGeminorumGem twins514P
GrusGruis Grucrane366B
Hercules HerculisHerHercules1,225P
HorologiumHorologiiHorclock249 L
HydraHydraeHyathe Hydra 1,303P
HydrusHydriHyi male water snake243B
Indus IndiIndIndian294B
LacertaLacertaeLaclizard201 H
LeoLeonisLeolion 947P
Leo MinorLeonis Minoris Lmilittle lion232H
Lepus LeporisLephare290P
MensaMensaeMentable154L, originally Mons Mensae
MicroscopiumMicroscopii Micmicroscope210L
Monoceros MonocerotisMonunicorn482H
MuscaMuscaeMusfly138B. Originally also called Apis.
NormaNormae Norsquare or level165L, originally Quadra Euclidis
OctansOctantisOct octant291L
OphiuchusOphiuchi OphOphiuchus, the serpent-bearer948P
OrionOrionisOriOrion, hunter594 P
PavoPavonisPavpeacock 378B
PegasusPegasiPeg Pegasus, the winged horse1,121P
PerseusPerseiPerPerseus, rescuer of Andromeda 615P
PhoenixPhoenicisPhe the phoenix469B
Pictor PictorisPicpainter or easel247L, originally Equuleus Pictoris
PiscesPiscium Pscfish889P
Piscis Austrinus Piscis AustriniPsAsouthern fish245 
PuppisPuppisPupship's stern673 formerly part of Argo Navis
PyxisPyxidis Pyxship's compass, previously part of Argo Navis221 L, originally Pyxis Nautica
ReticulumReticuli Retnet114L, originally Reticulus Rhomboidalis
SagittariusSagittariiSgearcher867 P
ScorpiusScorpiiScoscorpion 497P
SculptorSculptorisScl sculptor475L, originally Apparatus Sculptoris
ScutumScutiSctshield109H, originally Scutum Sobieskii
Sometimes divided into Serpens Caput and Serpens Cauda
Serpentis Serserpent637P
Sextans SextantisSexsextant314H, originally Sextans Uraniae
TaurusTauriTau bull797P
Telescopium TelescopiiTeltelescope252L
TriangulumTrianguliTritriangle132 P
Triangulum AustraleTrianguli Australis TrAsouthern triangle110B
Ursa MajorUrsae MajorisUMabig bear 1,280P
Ursa MinorUrsae Minoris UMilittle bear256P
Vela VelorumVelship's sail500formerly part of Argo Navis
VirgoVirginisVir virgin1,294P
VolansVolantis Volflying fish141B, originally Piscis Volans
VulpeculaVulpeculaeVullittle fox268 H, originally Vulpecula et Anser (fox and goose)


1. A. Fowler, ed.
First General Assembly, held at Rome, May 2nd to May 10th, 1922.
Transactions of the International Astronomical Union. Volume 1.
London: Imperial College Bookstall, no date [1922 ?].

Pages 23, 158, 207.  See also Transactions of the IAU, volume 4, page 221; volume 9, pages 66 and 77.

2. E. Delaporte.
Delimitation scientifique des constellations (tables et cartes).
Cambridge (UK): Cambridge University Press, 1930.

See also:
A. Levin.
Areas of the constellations.
British Astronomical Association Handbook (1935)

3. Aratus, in Callimachus, Hymns and Fragments; Lycophron; Aratus.
G. R. Mair, translator.
Loeb Classical Library.
London: William Heinemann; New York: G. P. Putnams, 1921.

Douglas Kidd.
Aratus. Phaenomena.
Cambridge: Cambridge University Press, 1997.

Very expensive scholarly book.

Aaron Poochigian, trans.
Aratus: Phaenomena.
Baltimore: Johns Hopkins University Press, 2010.

For Further Reading

Michael E. Bakich.
Cambridge Guide to the Constellations.
Cambridge University Press, 1995.


Theony Condos.
Star Myths of the Greeks and Romans: A Sourcebook Containing the Constellations of Pseudo-Eratosthenes and the Poetic Astronomy of Hyginus.
Phanes Press, 1997.

Sources in the Western tradition, for scholars.

Jacqueline Mitton.
Once Upon a Starry Night.
National Geographic Society, 2004.
or, by the same author,
Zoo in the Sky.
National Geographic Society, 1998.

H. A. Rey
Find the Constellations.
Houghton Mifflin, 1954. Several revised editions, most recent edition in 1988.

Classic children's book, by the author of the Curious George books. It has stood the test of time and is just as useful to adults wishing to learn the constellations. 

Julius D. W. Staal.
The New Patterns in the Sky. Myths and Legends of the Stars.
McDonald and Woodward, 1996. (Revision of a 1988 edition)

Recommended as an introduction at middle school and above.

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