In contemporary astronomy, 88 constellations are recognized by the International Astronomical Union (IAU). 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 1928Paul Stroobant, "(3) Commission des notations, des unités et de l'économie des publications", in: F.J.M. Stratton (ed.), Transactions of the International Astronomical Union: Vol. III. Third General Assembly held at Leiden, July 5 to July 13, 1928 (Cambridge: Cambridge University Press, 1929), pp. 17, 223 & 299. and published in 1930.

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 (which was later split into Carina, Vela and Puppis).Paul Stroobant, "Meetings of Standing Committees: (3) Notations", in: A. Fowler (ed.), Transactions of the International Astronomical Union: Vol. I. First General Assembly held at Rome, May 2nd to May 10th, 1922 (London: Imperial College Bookstall, 1922), pp. 158 & 207. After this, Eugène Joseph Delporte drew boundaries for each of the 88 constellations so that every point in the sky belonged to one constellation. Therefore, when an object is said to lie inside a particular constellation, it is understood to be positioned within these specified boundaries.

History

Some constellations are no longer recognized by the IAU but may appear in older star charts and other references. The most notable of these 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.

Modern constellations The 88 constellations depict 42 animals, 28 inanimate objects, 2 natural features (a river and a table mountain) and 16 humans or mythological characters (2 of them are centaurs, human-horse hybrids).

Abbreviations Each IAU constellation has an official three-letter abbreviation based on the Latin genitive form of the constellation name. As the genitive is similar to the base name, the majority of the abbreviations are the first three letters of the constellation name: Ori for Orion/Orionis, Ara for Ara/Arae, and Com for Coma Berenices. Some abbreviations use letters beyond the initial three to unambiguously identify the constellation: Aps for Apus/Apodis, CrA for Corona Australis, CrB for Corona Borealis, Crv for Corvus. (Crater is abbreviated Crt to prevent confusion with CrA.) In other 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 Sgr for Sagittarius. 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).

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. 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 starArea (sq. deg.) IAU NASANASA Dictionary of terms for Aerospace Use – table V, ConstellationsYearDiscovererAncient NameSplit fromNameVis. mag. AndromedaOED, 2nd edition And Andr Andromedae ancient Ptolemy Andromeda (mythological character) Alpheratz 2.06 722 Antlia Ant Antl Antliae 1756 Lacaille Antlia Pneumatica (air) pump α Antliae 4.25 239 ApusRandom House Dictionary Aps Apus Apodis 1598 Plancius, Keyser, de Houtman bird-of-paradise Paradys 3.83 206 Aquarius Aqr Aqar Aquarii ancient Ptolemy water-bearer Sadalsuud 2.87 980 Aquila Aql Aqil Aquilae ancient Ptolemy eagle Altair 0.76 652 Ara Ara Arae Arae ancient Ptolemy altar β Arae 2.84 237 Aries Ari Arie Arietis ancient Ptolemy ram Hamal 2.00 441 Auriga Aur Auri Aurigae ancient Ptolemy charioteer Capella 0.08 657 Boötes Boo Boot Boötis ancient Ptolemy herdsman Arcturus −0.05 907 Caelum Cae Cael Caeli 1756 Lacaille Caelum Sculptorium chisel or engraving tool α Caeli 4.46 125 Camelopardalis Cam Caml Camelopardalis 1613 Plancius giraffe β 4.02 757 Cancer Cnc Canc Cancri ancient Ptolemy crab Tarf 3.52 506 Canes Venatici CVn CVen Canum Venaticorum 1690 Hevelius hunting dogs Cor Caroli 2.81 465 Canis Major CMa CMaj Canis Majoris ancient Ptolemy greater dog Sirius −1.46 380 Canis Minor CMi CMin Canis Minoris ancient Ptolemy lesser dog Procyon 0.34 183 Capricornus Cap Capr Capricorni ancient Ptolemy sea goat Deneb Algedi 2.81 414 Carina Car Cari Carinae ancient; 1756 Ptolemy, Lacaille Argo Navis keel Canopus −0.74 494 Cassiopeia Cas Cass Cassiopeiae ancient Ptolemy Cassiopeia (mythological character) Schedar 2.24 598 Centaurus Cen Cent Centauri ancient Ptolemy centaur Alpha Centauri −0.27 1060 Cepheus Cep Ceph Cephei ancient Ptolemy Cepheus (mythological character) Alderamin 2.46 588 Cetus Cet Ceti Ceti ancient Ptolemy sea monster (later interpreted as a whale) Diphda 2.02 1231 Chamaeleon Cha Cham Chamaeleontis 1598 Plancius, Keyser, de Houtman chameleon α 4.06 132 Circinus Cir Circ Circini 1756 Lacaille compasses Xami 3.19 93 Columba Col Colm Columbae 1592 Plancius, Canis Major dove Phact 2.65 270 Coma Berenices Com Coma Comae Berenices ancient; 1536 Ptolemy; Caspar Vopel, Leo Berenice's hair β Comae Berenices 4.26 386 Corona Australis CrA CorA Coronae Australis ancient Ptolemy southern crown Meridiana 4.09 128 Corona Borealis CrB CorB Coronae Borealis ancient Ptolemy northern crown Alphecca 2.24 179 Corvus Crv Corv Corvi ancient Ptolemy crow Gienah 2.59 184 Crater Crt Crat Crateris ancient Ptolemy krater (bowl for mixing wine) δ Crateris 3.56 282 Crux Cru Cruc Crucis 1589 Plancius Centaurus cross Acrux 0.76 68 Cygnus Cyg Cygn Cygni ancient Ptolemy swan Deneb 1.25 804 Delphinus Del Dlph Delphini ancient Ptolemy dolphin Rotanev 3.62 189 Dorado Dor Dora Doradus 1598 Plancius, Keyser, de Houtman mahi-mahi (dolphinfish) α Doradus 3.26 179 Draco Dra Drac Draconis ancient Ptolemy dragon Eltanin 2.23 1083 Equuleus Equ Equl Equulei ancient Ptolemy pony Kitalpha 3.92 72 Eridanus Eri Erid Eridani ancient Ptolemy river Eridanus (mythology) Achernar 0.43 1138 Fornax For Forn Fornacis 1756 Lacaille Fourneau Chymique (chemical) furnace Dalim 3.92 398 Gemini Gem Gemi Geminorum ancient Ptolemy twins (Lugal-irra and Meslamta-ea, later Castor and Pollux) Pollux 1.14 514 Grus Gru Grus Gruis 1598 Plancius, Keyser, de Houtman crane (bird) Alnair 1.74 366 Hercules Her Herc Herculis ancient Ptolemy Hercules (mythological character) 2.81 1225 Horologium Hor Horo Horologii 1756 Lacaille pendulum clock α Horologii 3.85 249 Hydra Hya Hyda Hydrae ancient Ptolemy Hydra (mythological creature) Alphard 2.00 1303 Hydrus Hyi Hydi Hydri 1598 Plancius, Keyser, de Houtman lesser water snake β Hydri 2.80 243 Indus Ind Indi Indi 1598 Plancius, Keyser, de Houtman Indian (of unspecified type) α Indi 3.11 294 Lacerta Lac Lacr Lacertae 1690 Hevelius lizard Stellio 3.76 201 Leo Leo Leon Leonis ancient Ptolemy lion Regulus 1.35 947 Leo Minor LMi LMin Leonis Minoris 1690 Hevelius lesser lion Praecipua 3.83 232 Lepus Lep Leps Leporis ancient Ptolemy hare Arneb 2.59 290 Libra Lib Libr Librae ancient Ptolemy balance 2.61 538 Lupus Lup Lupi Lupi ancient Ptolemy wolf Uridim 2.30 334 Lynx Lyn Lync Lyncis 1690 Hevelius lynx α Lyncis 3.14 545 Lyra Lyr Lyra Lyrae ancient Ptolemy lyre / harp Vega 0.03 286 Mensa Men Mens Mensae 1756 Lacaille Mons Mensæ Table Mountain (South Africa) Hoerikwaggo 5.09 153 Microscopium Mic Micr Microscopii 1756 Lacaille microscope γ Microscopii 4.68 210 Monoceros Mon Mono Monocerotis 1613 Plancius unicorn β Monocerotis 3.74 482 Musca Mus Musc Muscae 1598 Plancius, Keyser, de Houtman fly α Muscae 2.69 138 Norma Nor Norm Normae 1756 Lacaille carpenter's level γ2 Normae 4.02 165 Octans Oct Octn Octantis 1756 Lacaille octant (instrument) ν Octantis 3.73 291 Ophiuchus Oph Ophi Ophiuchi ancient Ptolemy serpent-bearer Rasalhague 2.07 948 Orion Ori Orio Orionis ancient Ptolemy Orion (mythological character) Rigel 0.13 594 Pavo Pav Pavo Pavonis 1598 Plancius, Keyser, de Houtman peacock Peacock 1.94 378 Pegasus Peg Pegs Pegasi ancient Ptolemy Pegasus (mythological winged horse) Enif 2.40 1121 Perseus Per Pers Persei ancient Ptolemy Perseus (mythological character) Mirfak 1.82 615 Phoenix Phe Phoe Phoenicis 1598 Plancius, Keyser, de Houtman phoenix Ankaa 2.38 469 Pictor Pic Pict Pictoris 1756 Lacaille Equuleus Pictoris painter (originally 'painter's easel') α Pictoris 3.27 247 Pisces Psc Pisc Piscium ancient Ptolemy fish (plural) Alpherg 3.61 889 Piscis Austrinus PsA PscA Piscis Austrini ancient Ptolemy southern fish Fomalhaut 1.16 245 Puppis Pup Pupp Puppis ancient; 1756 Ptolemy, Lacaille Argo Navis poop deck Naos 2.25 673 Pyxis Pyx Pyxi Pyxidis 1756 Lacaille Pyxis Nautica mariner's compass α Pyxidis 3.67 221 Reticulum Ret Reti Reticuli 1756 Lacaille reticle Rhombus 3.32 114 Sagitta Sge Sgte Sagittae ancient Ptolemy arrow Telum 3.47 80 Sagittarius Sgr Sgtr Sagittarii ancient Ptolemy archer Kaus Australis 1.85 867 Scorpius Sco Scor Scorpii ancient Ptolemy scorpion Antares 0.91 497 Sculptor Scl Scul Sculptoris 1756 Lacaille Apparatus Sculptoris sculptor (originally 'sculptor's tools') α Sculptoris 4.30 475 Scutum Sct Scut Scuti 1690 Hevelius Scutum Sobiescianum shield (of Sobieski) Tianbian 3.83 109 SerpensSerpens 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. Ser Serp Serpentis ancient Ptolemy snake Unukalhai 2.62 637 Sextans Sex Sext Sextantis 1690 Hevelius sextant α Sextantis 4.49 314 Taurus Tau Taur Tauri ancient Ptolemy bull Aldebaran 0.86 797 Telescopium Tel Tele Telescopii 1756 Lacaille telescope α Telescopii 3.51 252 Triangulum Tri Tria Trianguli ancient Ptolemy triangle Alaybasan 3.00 132 Triangulum Australe TrA TrAu Trianguli Australis 1598 Plancius, Keyser, de Houtman southern triangle Atria 1.91 110 Tucana Tuc Tucn Tucanae 1598 Plancius, Keyser, de Houtman toucan Lang-Exster 2.85 295 Ursa Major UMa UMaj Ursae Majoris ancient Ptolemy great bear Alioth 1.77 1280 Ursa Minor UMi UMin Ursae Minoris ancient Ptolemy lesser bear Polaris 1.98 256 Vela Vel Velr Velorum ancient; 1756 Ptolemy, Lacaille Argo Navis sails γ Velorum 1.83 500 Virgo Vir Virg Virginis ancient Ptolemy virgin, maiden Spica 0.97 1294 Volans Vol Voln Volantis 1598 Plancius, Keyser, de Houtman, Piscis Volans flying fish γ Volantis 3.61 141 Vulpecula Vul Vulp Vulpeculae 1690 Hevelius Vulpecula cum Ansere little fox (originally, 'little fox with the goose') Anser 4.40 268

Asterisms