IAU designated constellations

IAU designated constellations in equirectangular projection (epoch B1875.0)

In contemporary astronomy, 88 constellations are recognized by the International Astronomical Union (IAU). ^[1] Each constellation is a region of the sky bordered by arcs of right ascension and declination, together covering the entire celestial sphere. Their boundaries were officially adopted by the International Astronomical Union in 1928 and published in 1930. ^[2]

The ancient Mesopotamians and later the Greeks established most of the northern constellations in international use today, listed by the Roman-Egyptian astronomer Ptolemy. The constellations along the ecliptic are called the zodiac. When explorers mapped the stars of the southern skies, European astronomers proposed new constellations for that region, as well as ones to fill gaps between the traditional constellations. Because of their Roman and European origins, every constellation has a Latin name. In 1922, the International Astronomical Union adopted three-letter abbreviations for 89 constellations, the modern list of 88 plus Argo. After this, Eugène Joseph Delporte drew up boundaries for each of the 88 constellations so that every point in the sky belonged to one constellation. ^{[1] [2]} When astronomers say that an object lies in a particular constellation, they mean that it is positioned within these specified boundaries.

History

Main articles: History of the constellations and Former constellations

Some constellations are no longer recognized by the IAU, but may appear in older star charts and other references. Most notable is Argo Navis, which was one of Ptolemy's original 48 constellations. In the 1750s the French astronomer Nicolas Louis de Lacaille divided this into three separate constellations: Carina, Puppis, and Vela. ^[3]

Modern constellations

The 88 constellations depict 42 animals, 29 inanimate objects, and 17 humans or mythological characters.

Abbreviations

Each IAU constellation has an official three-letter abbreviation based on the genitive form of the constellation name. As the genitive is similar to the base name, the majority of the abbreviations are just the first three letters of the constellation name: Ori for Orion/Orionis, Ara for Ara/Arae, and Com for Coma Berenices/Comae Berenices. In some cases, the abbreviation contains letters from the genitive not appearing in the base name (as in Hyi for Hydrus/Hydri, to avoid confusion with Hydra, abbreviated Hya; and Sge for Sagitta/Sagittae, to avoid confusion with Sagittarius, abbreviated Sgr). Some abbreviations use letters beyond the initial three to unambiguously identify the constellation (for example when the name and its genitive differ in the first three letters): Aps for Apus/Apodis, CrA for Corona Australis, CrB for Corona Borealis, Crv for Corvus. (Crater is abbreviated Crt to prevent confusion with CrA.) When letters are taken from the second word of a two-word name, the first letter from the second word is capitalised: CMa for Canis Major, CMi for Canis Minor. Two cases are ambiguous: Leo for the constellation Leo could be mistaken for Leo Minor (abbreviated LMi), and Tri for Triangulum could be mistaken for Triangulum Australe (abbreviated TrA). ^[4]

In addition to the three-letter abbreviations used today, the IAU also introduced four-letter abbreviations in 1932. The four-letter abbreviations were repealed in 1955 and are now obsolete, but were included in the NASA Dictionary of Technical Terms for Aerospace Use (NASA SP-7) published in 1965. ^[5] These are labeled "NASA" in the table below and are included here for reference only.

List

For help with the literary English pronunciations, see the pronunciation key. There is considerable diversity in how Latinate names are pronounced in English. For traditions closer to the original, see Latin spelling and pronunciation.

Constellation	Abbreviations		Genitive	Origin	Meaning	Brightest star
	IAU [6]	NASA [7]				Name	Vis. mag.
Andromeda /ænˈdrɒmɪdə/ [8]	And	Andr	Andromedae	ancient (Ptolemy)	Andromeda (The chained maiden or princess)	Alpheratz	2.06
Antlia /ˈæntliə/ [8]	Ant	Antl	Antliae	1763, Lacaille	air pump	α Antliae	4.25
Apus /ˈeɪpəs/ [9]	Aps	Apus	Apodis /ˈæpoʊdɪs/ [9]	1603, Uranometria , created by Keyser and de Houtman	Bird-of-paradise/Exotic Bird/Extraordinary Bird	α Apodis	3.83
Aquarius /əˈkwɛəriəs/ [8]	Aqr	Aqar	Aquarii	ancient (Ptolemy)	water-bearer	Sadalsuud	2.87
Aquila /ˈækwɪlə/ [8]	Aql	Aqil	Aquilae	ancient (Ptolemy)	eagle	Altair	0.76
Ara /ˈɛərə/ [9]	Ara	Arae	Arae /ˈɛəriː/ [9]	ancient (Ptolemy)	altar	β Arae	2.84
Aries /ˈɛər(i)iːz/ [8] [9]	Ari	Arie	Arietis /əˈraɪ.ɪtɪs/ [9]	ancient (Ptolemy)	ram	Hamal	2.00
Auriga /ɔːˈraɪɡə/ [8] [9]	Aur	Auri	Aurigae /ɔːˈraɪdʒiː/ [9]	ancient (Ptolemy)	charioteer	Capella	0.08
Boötes /boʊˈoʊtiːz/ [8]	Boo	Boot	Boötis	ancient (Ptolemy)	herdsman	Arcturus	-0.05
Caelum /ˈsiːləm/ [9]	Cae	Cael	Caeli /ˈsiːlaɪ/ [9]	1763, Lacaille	chisel or engraving tool	α Caeli	4.46
Camelopardalis /kəˌmɛloʊˈpɑːrdəlɪs/ [9]	Cam	Caml	Camelopardalis /kəˌmɛloʊˈpɑːrdəlɪs/ [9]	1613, Plancius [note 1]	giraffe	β Camelopardalis	4.02
Cancer /ˈkænsər/ [8]	Cnc	Canc	Cancri	ancient (Ptolemy)	crab	β Cancri	3.52
Canes Venatici /ˈkeɪniːzvɪˈnætɪsaɪ/ [9]	CVn	CVen	Canum Venaticorum	1690, Firmamentum Sobiescianum, Hevelius	hunting dogs	Cor Caroli	2.81
Canis Major /ˈkeɪnɪsˈmeɪdʒər/ [9]	CMa	CMaj	Canis Majoris	ancient (Ptolemy)	greater dog	Sirius	-1.46
Canis Minor /ˈkeɪnɪsˈmaɪnər/ [9]	CMi	CMin	Canis Minoris	ancient (Ptolemy)	lesser dog	Procyon	0.34
Capricornus /ˌkæprɪˈkɔːrnəs/ [9]	Cap	Capr	Capricorni /ˌkæprɪˈkɔːrnaɪ/ [9]	ancient (Ptolemy)	sea goat	Deneb Algedi	2.83
Carina /kəˈraɪnə/ [8]	Car	Cari	Carinae	1763, Lacaille, split from Argo Navis	keel	Canopus	-0.74
Cassiopeia /ˌkæsioʊˈpiːə/ [8] [9]	Cas	Cass	Cassiopeiae /ˌkæsioʊˈpiːiː/ [9]	ancient (Ptolemy)	Cassiopeia (mythological character)	Schedar	2.24
Centaurus /sɛnˈtɔːrəs/ [8]	Cen	Cent	Centauri	ancient (Ptolemy)	centaur	Alpha Centauri	-0.27
Cepheus /ˈsiːfiəs/ [9]	Cep	Ceph	Cephei /ˈsiːfiaɪ/ [9]	ancient (Ptolemy)	Cepheus (mythological character)	Alderamin	2.46
Cetus /ˈsiːtəs/ [9]	Cet	Ceti	Ceti /ˈsiːtaɪ/ [9]	ancient (Ptolemy)	sea monster (later interpreted as a whale)	Diphda	2.02
Chamaeleon /kəˈmiːliən/ [8]	Cha	Cham	Chamaeleontis	1603, Uranometria , created by Keyser and de Houtman	chameleon	α Chamaeleontis	4.06
Circinus /ˈsɜːrsɪnəs/ [8]	Cir	Circ	Circini	1763, Lacaille	compasses	α Circini	3.19
Columba /koʊˈlʌmbə/ [8]	Col	Colm	Columbae	1592, Plancius, split from Canis Major	dove	Phact	2.65
Coma Berenices /ˈkoʊməbɛrəˈnaɪsiːz/ [9]	Com	Coma	Comae Berenices /ˈkoʊmiːbɛrəˈnaɪsiːz/ [9]	1536, Caspar Vopel, [10] split from Leo	Berenice's hair	β Comae Berenices	4.26
Corona Australis /koʊˈroʊnəɔːˈstrælɪs,-ˈstreɪ-/ [8] [9]	CrA	CorA	Coronae Australis	ancient (Ptolemy)	southern crown	α Coronae Australis	4.10
Corona Borealis /koʊˈroʊnəˌbɔːriˈælɪs,-ˈeɪlɪs/ [8] [9]	CrB	CorB	Coronae Borealis	ancient (Ptolemy)	northern crown	Alphecca	2.24
Corvus /ˈkɔːrvəs/ [8]	Crv	Corv	Corvi	ancient (Ptolemy)	crow	Gienah	2.59
Crater /ˈkreɪtər/ [8]	Crt	Crat	Crateris	ancient (Ptolemy)	cup	δ Crateris	3.56
Crux /ˈkrʌks/ [8]	Cru	Cruc	Crucis	1589, Plancius , split from Centaurus	southern cross	Acrux	0.76
Cygnus /ˈsɪɡnəs/ [8]	Cyg	Cygn	Cygni	ancient (Ptolemy)	swan or Northern Cross	Deneb	1.25
Delphinus /dɛlˈfaɪnəs/ [8]	Del	Dlph	Delphini	ancient (Ptolemy)	dolphin	β Delphini	3.62
Dorado /dəˈrɑːdoʊ/ [11]	Dor	Dora	Doradus	1603, Uranometria , created by Keyser and de Houtman	dolphinfish	α Doradus	3.28
Draco /ˈdreɪkoʊ/ [9]	Dra	Drac	Draconis /drəˈkoʊnɪs/ [9]	ancient (Ptolemy)	dragon	Eltanin	2.23
Equuleus /ɪˈkwuːliəs/ [9]	Equ	Equl	Equulei /ɪˈkwuːliaɪ/ [9]	ancient (Ptolemy)	pony	α Equulei	3.92
Eridanus /ɪˈrɪdənəs/ [9]	Eri	Erid	Eridani /ɪˈrɪdənaɪ/ [9]	ancient (Ptolemy)	river Eridanus (mythology)	Achernar	0.46
Fornax /ˈfɔːrnæks/	For	Forn	Fornacis	1763, Lacaille	chemical furnace	α Fornacis	3.85
Gemini /ˈdʒɛmɪnaɪ/ [8]	Gem	Gemi	Geminorum	ancient (Ptolemy)	twins	Pollux	1.14
Grus /ˈɡrʌs/ [9]	Gru	Grus	Gruis /ˈɡruːɪs/ [9]	1603, Uranometria , created by Keyser and de Houtman	crane	Alnair	1.74
Hercules /ˈhɜːrkjʊliːz/ [9]	Her	Herc	Herculis	ancient (Ptolemy)	Hercules (mythological character)	Kornephoros	2.81
Horologium /ˌhɒrəˈlɒdʒiəm,-ˈloʊ-/ [8] [9]	Hor	Horo	Horologii	1763, Lacaille	pendulum clock	α Horologii	3.85
Hydra /ˈhaɪdrə/ [8]	Hya	Hyda	Hydrae	ancient (Ptolemy)	Hydra (mythological creature)	Alphard	2.00
Hydrus /ˈhaɪdrəs/ [8]	Hyi	Hydi	Hydri	1603, Uranometria , created by Keyser and de Houtman	lesser water snake	β Hydri	2.80
Indus /ˈɪndəs/ [8]	Ind	Indi	Indi	1603, Uranometria , created by Keyser and de Houtman	Indian (of unspecified type)	α Indi	3.11
Lacerta /ləˈsɜːrtə/ [8]	Lac	Lacr	Lacertae	1690, Firmamentum Sobiescianum, Hevelius	lizard	α Lacertae	3.76
Leo /ˈliːoʊ/ [8]	Leo	Leon	Leonis	ancient (Ptolemy)	lion	Regulus	1.35
Leo Minor /ˈliːoʊˈmaɪnər/ [8]	LMi	LMin	Leonis Minoris	1690, Firmamentum Sobiescianum, Hevelius	lesser lion	46 Leonis Minoris	3.83
Lepus /ˈliːpəs/ [9]	Lep	Leps	Leporis /ˈlɛpərɪs/ [8] [9]	ancient (Ptolemy)	hare	Arneb	2.59
Libra /ˈlaɪbrə,ˈliː-/ [8]	Lib	Libr	Librae	ancient (Ptolemy)	balance	Zubeneschemali	2.61
Lupus /ˈljuːpəs/ [8]	Lup	Lupi	Lupi	ancient (Ptolemy)	wolf	α Lupi	2.30
Lynx /ˈlɪŋks/ [8]	Lyn	Lync	Lyncis	1690, Firmamentum Sobiescianum, Hevelius	lynx	α Lyncis	3.14
Lyra /ˈlaɪrə/ [8]	Lyr	Lyra	Lyrae	ancient (Ptolemy)	lyre / harp	Vega	0.02
Mensa /ˈmɛnsə/ [8]	Men	Mens	Mensae	1763, Lacaille, as Mons Mensæ	Table Mountain (South Africa)	α Mensae	5.09
Microscopium /ˌmaɪkroʊˈskɒpiəm/	Mic	Micr	Microscopii	1763, Lacaille	microscope	γ Microscopii	4.68
Monoceros /məˈnɒsɪrəs/ [8] [9]	Mon	Mono	Monocerotis	1613, Plancius	unicorn	β Monocerotis	3.74
Musca /ˈmʌskə/ [9]	Mus	Musc	Muscae /ˈmʌsiː/ [8] [9]	1603, Uranometria , created by Keyser and de Houtman	fly	α Muscae	2.69
Norma /ˈnɔːrmə/ [8]	Nor	Norm	Normae /ˈnɔːrmiː/ [8]	1763, Lacaille	carpenter's level	γ2 Normae	4.02
Octans /ˈɒktænz/ [9]	Oct	Octn	Octantis /ɒkˈtæntɪs/ [9]	1763, Lacaille	octant (instrument)	ν Octantis	3.73
Ophiuchus /ˌɒfiˈjuːkəs/ [8]	Oph	Ophi	Ophiuchi	ancient (Ptolemy)	serpent-bearer	Rasalhague	2.07
Orion /oʊˈraɪən/ [8]	Ori	Orio	Orionis /oʊˈraɪənɪs,ˌɒriˈoʊnɪs/ [9]	ancient (Ptolemy)	Orion (mythological character)	Rigel	0.13
Pavo /ˈpeɪvoʊ/ [8] [9]	Pav	Pavo	Pavonis /pəˈvoʊnɪs/ [9]	1603, Uranometria , created by Keyser and de Houtman	peacock	Peacock	1.94
Pegasus /ˈpɛɡəsəs/ [8]	Peg	Pegs	Pegasi	ancient (Ptolemy)	Pegasus (mythological winged horse)	Enif	2.40
Perseus /ˈpɜːrsiəs/ [9]	Per	Pers	Persei /ˈpɜːrsiaɪ/ [9]	ancient (Ptolemy)	Perseus (mythological character)	Mirfak	1.82
Phoenix /ˈfiːnɪks/ [8]	Phe	Phoe	Phoenicis /fɪˈnaɪsɪs/	1603, Uranometria , created by Keyser and de Houtman	phoenix	Ankaa	2.38
Pictor /ˈpɪktər/ [9]	Pic	Pict	Pictoris /pɪkˈtɔːrɪs/ [9]	1763, Lacaille, as Equuleus Pictoris	easel	α Pictoris	3.27
Pisces /ˈpaɪsiːz,ˈpɪ-/ [8] [9]	Psc	Pisc	Piscium /ˈpɪʃiəm/ [9]	ancient (Ptolemy)	fishes	Alpherg	3.61
Piscis Austrinus /ˈpaɪsɪsɔːˈstraɪnəs/	PsA	PscA	Piscis Austrini	ancient (Ptolemy)	southern fish	Fomalhaut	1.16
Puppis /ˈpʌpɪs/ [9]	Pup	Pupp	Puppis /ˈpʌpɪs/ [9]	1763, Lacaille, split from Argo Navis	poop deck	Naos	2.25
Pyxis /ˈpɪksɪs/ [8]	Pyx	Pyxi	Pyxidis	1763, Lacaille	mariner's compass	α Pyxidis	3.67
Reticulum /rɪˈtɪkjʊləm/ [8]	Ret	Reti	Reticuli	1763, Lacaille	eyepiece graticule	α Reticuli	3.32
Sagitta /səˈdʒɪtə/ [8]	Sge	Sgte	Sagittae	ancient (Ptolemy)	arrow	γ Sagittae	3.47
Sagittarius /sædʒɪˈtɛəriəs/ [8]	Sgr	Sgtr	Sagittarii	ancient (Ptolemy)	archer	Kaus Australis	1.85
Scorpius /ˈskɔːrpiəs/ [8]	Sco	Scor	Scorpii	ancient (Ptolemy)	scorpion	Antares	0.91
Sculptor /ˈskʌlptər/ [8]	Scl	Scul	Sculptoris	1763, Lacaille	sculptor	α Sculptoris	4.30
Scutum /ˈskjuːtəm/ [8]	Sct	Scut	Scuti	1690, Firmamentum Sobiescianum, Hevelius	shield (of Sobieski)	α Scuti	3.83
Serpens [12] /ˈsɜːrpɛnz/	Ser	Serp	Serpentis	ancient (Ptolemy)	snake	Unukalhai	2.62
Sextans /ˈsɛkstənz/ [9]	Sex	Sext	Sextantis /sɛksˈtæntɪs/ [9]	1690, Firmamentum Sobiescianum, Hevelius	sextant	α Sextantis	4.49
Taurus /ˈtɔːrəs/ [8]	Tau	Taur	Tauri	ancient (Ptolemy)	bull	Aldebaran	0.86
Telescopium /ˌtɛlɪˈskɒpiəm/	Tel	Tele	Telescopii	1763, Lacaille	telescope	α Telescopii	3.51
Triangulum /traɪˈæŋɡjʊləm/	Tri	Tria	Trianguli	ancient (Ptolemy)	triangle	β Trianguli	3.00
Triangulum Australe /traɪˈæŋɡjʊləmɔːˈstræliː,-ˈstreɪ-/	TrA	TrAu	Trianguli Australis	1603, Uranometria , created by Keyser and de Houtman	southern triangle	Atria	1.91
Tucana /tjuːˈkeɪnə/	Tuc	Tucn	Tucanae	1603, Uranometria , created by Keyser and de Houtman	toucan	α Tucanae	2.86
Ursa Major /ˌɜːrsəˈmeɪdʒər/ [8]	UMa	UMaj	Ursae Majoris	ancient (Ptolemy)	great bear	Alioth	1.77
Ursa Minor /ˌɜːrsəˈmaɪnər/ [8]	UMi	UMin	Ursae Minoris	ancient (Ptolemy)	lesser bear	Polaris	1.98
Vela /ˈviːlə/ [8]	Vel	Velr	Velorum /vɪˈloʊrəm/	1763, Lacaille, split from Argo Navis	sails	γ Velorum	1.83
Virgo /ˈvɜːrɡoʊ/ [8]	Vir	Virg	Virginis	ancient (Ptolemy)	virgin or maiden	Spica	0.97
Volans /ˈvoʊlænz/ [9]	Vol	Voln	Volantis /voʊˈlæntɪs/ [9]	1603, Uranometria , created by Keyser and de Houtman, as Piscis Volans	flying fish	γ2 Volantis	3.75
Vulpecula /vʌlˈpɛkjʊlə/ [8]	Vul	Vulp	Vulpeculae	1690, Firmamentum Sobiescianum, Hevelius, as Vulpecula cum Ansere	fox	α Vulpeculae	4.40

Asterisms

Main article: Asterism (astronomy)

Various other unofficial patterns exist alongside the constellations. These are known as "asterisms". Some are part of one larger constellation while others consists of stars in two adjoining constellations. Examples include the Big Dipper/Plough in Ursa Major; the Teapot in Sagittarius; the Square of Pegasus in Pegasus and Andromeda; and the False Cross in Carina and Vela.

See also

• Lists of astronomical objects
• List of constellations by area
• Biblical names of stars
• Lists of stars by constellation
• Constellation family
• Galactic quadrant

Notes

1. The constellations Camelopardalis, Columba, and Monoceros, formed by Petrus Plancius in 1592 and in 1613, are often erroneously attributed to Jacob Bartsch and Augustin Royer.

References

1. "The Constellations". International Astronomical Union . Retrieved 17 June 2025.
2. Eugène Delporte; International Astronomical Union (1930). Délimitation scientifique des constellations. At the University press.
3. "Argo Navis". Ian Ridpath’s Star Tales. Retrieved 28 April 2025.
4. Russell, Henry Norris (1922). "The New International Symbols for the Constellations". Popular Astronomy. 30: 469. Bibcode:1922PA.....30..469R.
5. "Constellations". Ian Ridpath . Retrieved 30 January 2023.
6. "The Constellations". International Astronomical Union . Retrieved 17 June 2025.
7. NASA Dictionary of terms for Aerospace Use – table V, Constellations
8. OED, 2nd edition
9. Random House Dictionary
10. "Comae Berenices" . Retrieved 23 November 2020.
11. "Definition of dorado". Collins English Dictionary . Archived from the original on 28 November 2012. Retrieved 28 November 2012.
12. Serpens may be divided into Serpens Cauda (serpent's tail) and Serpens Caput (serpent's head), but these disjoint areas are considered part of the same constellation by the IAU.

External links

• The Constellations 1 – Ian Ridpath's history of IAU constellations.
• Ian Ridpath's Star Tales: Constellation Mythology and History – Ian Ridpath's Star Tales.
• VizieR – CDS's archive of constellation boundaries. The text file constbnd.dat gives the 1875.0 coordinates of the vertices of the constellation regions, together with the constellations adjacent to each boundary segment.