Theadjectival forms of the names of astronomical bodies are not always easily predictable. Attested adjectival forms of the larger bodies are listed below, along with the two small Martian moons; in some cases they are accompanied by theirdemonymic equivalents, which denote hypothetical inhabitants of these bodies.
For Classical (Greco-Roman) names, the adjectival and demonym forms normally derive from theoblique stem, which may differ from thenominative form used in English for the noun form. For instance, for a large portion of names ending in-s, the oblique stem and therefore the English adjective changes the-s to a-d, -t, or-r, as in Mars–Martian, Pallas–Palladian and Ceres–Cererian;[note 1]occasionally an-n has been lost historically from the nominative form, and reappears in the oblique and therefore in the English adjective, as in Pluto–Plutonian and Atlas–Atlantean.
Many of the more recent or more obscure names are only attested in mythological or literary contexts, rather than in specifically astronomical contexts. Forms ending in-ish or-ine, such as "Puckish", are not included below if a derivation in-an is also attested. Rare forms, or forms only attested with spellings not in keeping with theIAU-approved spelling (such asc fork), are shown initalics.
The suffix-ian is always unstressed: that is,/iən/. The related ending-ean, from ane in the root plus a suffix-an, has traditionally been stressed (that is,/ˈiːən/) if thee is longē in Latin (or is from⟨η⟩ē in Greek); but if thee is short in Latin, the suffix is pronounced the same as-ian. In practice forms ending in-ean may be pronounced as if they were spelled-ian even if thee is long in Latin. This dichotomy should be familiar from the dual pronunciations ofCaribbean as/ˌkærɪˈbiːən/KARR-ə-BEE-ən and/kəˈrɪbiən/kə-RIB-i-ən.
| Name | Adjective | Demonym |
|---|---|---|
| asteroid | asteroidal,asteroidic | Asterite |
| comet | cometary | |
| cosmos,universe | cosmic,cosmian, universal | |
| ecliptic | ecliptical, zodiacal | |
| galaxy | galactic,galactian | |
| meteoroid | meteoroidal | |
| nebula | nebular | |
| planet | planetary,planetic | |
| planetoid | planetoidal | |
| quasar | quasaric, quasarian | |
| sky | celestial | |
| star | astral, sidereal,siderean, stellar | |
| supernova | supernovan |
Derivative forms of constellations are used primarily formeteor showers. Thegenitive forms of the constellations are used to name stars. (SeeList of constellations.) Other adjectival forms are less common.
| Name | Adjective | Derivative |
|---|---|---|
| Andromeda | Andromedan | Andromedid |
| Aquarius | Aquarian | Aquariid |
| Aries | Arian | Arietid |
| Auriga | Aurigal | Aurigid |
| Boötes | Bootid | |
| Cancer | Cancerian | Cancrid |
| Carina | Carinal | Carinid |
| Capricorn | Capricornian | Capricornid |
| Centaurus | Centaurean, Centaurian | Centaurid |
| Cetus | Cetid | |
| Coma Berenices | Comal | Coma Berenicid |
| Corona Austrina | Coronal | Corona Austrinid |
| Crux | Crucial | Crucid |
| Cygnus | Cygnean | Cygnid |
| Dorado | Doradid | |
| Draco | Draconic | Draconid |
| Eridanus | Eridanid | |
| Gemini | Geminian | Geminid |
| Hydra,Hydrus | Hydrid | |
| Leo | Leonic, Leonian, Leonean | Leonid |
| Leo Minor | Leo Minorid | |
| Libra | Libran | Librid |
| Lyra | Lyrid | |
| Monoceros | Monocerotid | |
| Norma | Normid | |
| Ophiuchus | Ophiuchid | |
| Orion | Orionid | |
| Pavo | Pavonid | |
| Pegasus | Pegasean, Pegasarian | Pegasid |
| Perseus | Perseid | |
| Phoenix | Phoenicean | Phoenicid |
| Pisces | Piscean, Piscian | Piscid |
| Piscis Austrinus | Piscis Austrinid | |
| Puppis | Puppid | |
| Sagittarius | Sagittarian | Sagittariid |
| Scorpius | Scorpian, Scorpionic | Scorpiid |
| Taurus | Taurean, Taurian | Taurid |
| Ursa Major,Ursa Minor | Ursal | Ursid |
| Vela | Velar, Velic | Velid |
| Virgo | Virginal, Virginian | Virginid |
| zodiac | zodiacal |
| Name | Adjective | Demonym |
|---|---|---|
| Sun, Sol,Helios | Solar, Heliacal,Phoebean, Phebean | Solarian |
| Name | Adjective | Demonym |
|---|---|---|
| Ceres | Cererian,[1]Cererean[2] | Cererian |
| Earth,Terra, Tellus,Gaia, Gaea | earthly, Terran, Terrestrial,Terrene, Tellurian,[3]Telluric, Gaian, Gaean | Earthling, Terran, Terrestrial, Tellurian, Earthian, Earther, Earthican |
| Eris | Eridian[4] | |
| Haumea | Haumean[5] | |
| Jupiter | Jovian, Jupiterian,Zeusian | Jovian |
| Makemake | Makemakean[6] | |
| Mars | Martian, Martial,Arean[7] | Martian |
| Mercury; Hermes (in the evening), Apollo (in the morning) | Mercurian, Mercurial, Hermean/Hermeian,Cyllenian,[8]Cyllenean | Mercurian, Hermean |
| Neptune | Neptunian,Neptunial,Poseidean[9] | Neptunian |
| Orcus | Orcean,[10] Orcan | |
| Pallas | Palladian | |
| Pluto | Plutonic, Plutonian | Plutonian |
| Saturn | Saturnian, Saturnine, Cronian,[9] Kronian,[11]Saturnial[12] | Saturnian |
| Sedna | Sednian[13] | |
| Uranus | Uranian,Caelian | Uranian |
| Vesta | Vestian,[14][15] Vestan,[16][17]Vestalian | Vestan, Vestian |
| Venus; Hesperus,Vesper (in the evening), Eosphorus,Phosphorus, Phosphor (in the morning), Lucifer (in the day) | Venerian, Venusian,Cytherean,[18]Cytherian,[19] Hesperian,[20]Luciferian,[21]Phosphorian,[22]Aphroditan[23] | Venusian, Cytherean |
| Name | Adjective | Demonym |
|---|---|---|
| Moon (Luna,Selene) | Lunar, Selenian, Cynthian | Lunarian, Selenite |
| Deimos | Deimian[24] | |
| Phobos | Phobian[25] | |
| Name | Adjective, demonym |
|---|---|
| Callisto | Callistoan,[26] Callistonian[27] |
| Europa | Europan[28] |
| Ganymede | Ganymedean,[29] Ganymedian |
| Io | Ionian[30] |
| Name | Adjective, demonym |
|---|---|
| Dione | Dionean[31][32] |
| Enceladus | Enceladean,[33][34] Enceladan[35][36] |
| Hyperion | Hyperionian[37] |
| Iapetus | Iapetian,[38] Japetian |
| Mimas | Mimantean,[34] Mimantian[39] |
| Rhea | Rhean[40][41] |
| Tethys | Tethyan[42][43] |
| Titan | Titanian/taɪˈteɪniən/,[44]Titanean[45] |
| Name | Adjective, demonym |
|---|---|
| Ariel | Arielian[46] |
| Miranda | Mirandan,[47] Mirandian[48] |
| Oberon | Oberonian[49] |
| Titania | Titanian/tɪˈtɑːniən/[50] |
| Umbriel | Umbrielian[50] |
| Name | Adjective, demonym |
|---|---|
| Triton | Tritonian[51] |
| Charon | Charonian[52] |
| Dysnomia | Dysnomian |
| Name | Adjective |
|---|---|
| Milky Way Galaxy | Galactic,[53]Lacteal[54] |
| Andromeda Galaxy | Andromedan |
| Magellanic Clouds | Magellanic |
