Constellation

Orion constellation Hevelius.jpg
Orion IAU.svgOrionCC.jpg
  • Top: Baroque drawing of the constellation Orion from Johannes Hevelius' Celestial catalogue, showing the stars as they would appear to an observer looking down upon the imaginary celestial sphere from the outside
  • Bottom: Contemporary map of Orion from the IAU and photography of the night sky

A constellation is a group of stars that forms an imaginary outline or pattern on the celestial sphere, typically representing an animal, mythological person or creature, a god, or an inanimate object.[1]

The origins of the earliest constellations likely go back to prehistory. People used them to relate stories of their beliefs, experiences, creation, or mythology. Different cultures and countries adopted their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. Adoption of constellations has changed significantly over time. Many have changed in size or shape. Some became popular, only to drop into obscurity. Others were limited to single cultures or nations.

The 48 traditional Western constellations are Greek. They are given in Aratus' work Phenomena and Ptolemy's Almagest, though their origin probably predates these works by several centuries. Constellations in the far southern sky were added from the 15th century until the mid-18th century when European explorers began traveling to the Southern Hemisphere. Twelve ancient constellations belong to the zodiac (straddling the ecliptic, which the Sun, Moon, and planets all traverse). The origins of the zodiac remain historically uncertain; its astrological divisions became prominent c. 400 BC in Babylonian or Chaldean astronomy,[2] probably dates back to prehistory.

In 1928, the International Astronomical Union (IAU) formally accepted 88 modern constellations, with contiguous boundaries that together cover the entire celestial sphere.[3][4] Any given point in a celestial coordinate system lies in one of the modern constellations. Some astronomical naming systems include the constellation where a given celestial object is found to convey its approximate location in the sky. The Flamsteed designation of a star, for example, consists of a number and the genitive form of the constellation name.

Other star patterns or groups called asterisms are not constellations per se but are used by observers to navigate the night sky. Asterisms often refer to several stars within a constellation or may share stars with several constellations. Examples include the Pleiades and Hyades within the constellation Taurus and the False Cross split between the southern constellations Carina and Vela, or Venus' Mirror in the constellation of Orion.[5][6]

Terminology

The word "constellation" comes from the Late Latin term cōnstellātiō, which can be translated as "set of stars"; it came into use in English during the 14th century.[7] The Ancient Greek word for constellation is ἄστρον. A more modern astronomical sense of the term "constellation" is simply as a recognisable pattern of stars whose appearance is associated with mythological characters or creatures, or earthbound animals, or objects.[1] It can also specifically denote the officially recognized 88 named constellations used today.[8]

Colloquial usage does not draw a sharp distinction between "constellations" and smaller "asterisms" (pattern of stars), yet the modern accepted astronomical constellations employ such a distinction. E.g., the Pleiades and the Hyades are both asterisms, and each lies within the boundaries of the constellation of Taurus. Another example is the popular northern asterism known as the Big Dipper (US) or the Plough (UK), composed of the seven brightest stars within the area of the IAU-defined constellation of Ursa Major. The southern False Cross asterism includes portions of the constellations Carina and Vela.

A constellation (or star), viewed from a particular latitude on Earth, that never sets below the horizon is termed circumpolar. From the North Pole or South Pole, all constellations south or north of the celestial equator are circumpolar. Depending on the definition, equatorial constellations may include those that lie between declinations 45° north and 45° south,[9] or those that pass through the declination range of the ecliptic or zodiac ranging between 23½° north, the celestial equator, and 23½° south.[10][11]

Although stars in constellations appear near each other in the sky, they usually lie at a variety of distances away from the Earth. Since stars have their own independent motions, all constellations will change slowly over time. After tens to hundreds of thousands of years, familiar outlines will generally become unrecognizable.[12] Astronomers can predict the past or future constellation outlines by measuring individual stars' common proper motions or cpm[13] by accurate astrometry[14][15] and their radial velocities by astronomical spectroscopy.[16]

Other Languages
Afrikaans: Sterrebeeld
Alemannisch: Sternbild
العربية: كوكبة
armãneashti: Constelație
asturianu: Constelación
Avañe'ẽ: Mbyjaty
azərbaycanca: Bürc
Bân-lâm-gú: Seng-chō
башҡортса: Йондоҙлоҡ
беларуская: Сузор’е
беларуская (тарашкевіца)‎: Сузор’е
български: Съзвездие
Boarisch: Steanbuid
bosanski: Sazviježđe
brezhoneg: Steredeg
Чӑвашла: Çăлтăрлăх
čeština: Souhvězdí
Cymraeg: Cytser
davvisámegiella: Nástegovva
Deutsch: Sternbild
eesti: Tähtkuju
Ελληνικά: Αστερισμός
español: Constelación
Esperanto: Konstelacio
euskara: Konstelazio
فارسی: صورت فلکی
français: Constellation
Gaeilge: Réaltbhuíon
Gàidhlig: Reul-bhad
ગુજરાતી: નક્ષત્ર
客家語/Hak-kâ-ngî: Sên-chho
한국어: 별자리
हिन्दी: तारामंडल
hrvatski: Zviježđe
Ido: Stelaro
Bahasa Indonesia: Rasi bintang
interlingua: Constellation
íslenska: Stjörnumerki
italiano: Costellazione
Basa Jawa: Rasi lintang
Kiswahili: Kundinyota
Kreyòl ayisyen: Konstelasyon
kurdî: Komstêr
Кыргызча: Топ жылдыз
Latina: Constellatio
latviešu: Zvaigznājs
Lëtzebuergesch: Stärebild
lietuvių: Žvaigždynas
Limburgs: Starebeeld
lingála: Nzɔ́tɔ
Lingua Franca Nova: Constela
magyar: Csillagkép
македонски: Соѕвездие
مازِرونی: فلکی صورتون
Bahasa Melayu: Buruj
Mìng-dĕ̤ng-ngṳ̄: Sĭng-cô̤
မြန်မာဘာသာ: ကြယ်အုပ်စု
Nāhuatl: Miaccītlalli
Nederlands: Sterrenbeeld
Nedersaksies: Konstelloatsie
नेपाली: तारामण्डल
日本語: 星座
norsk nynorsk: Stjernebilete
Nouormand: Constellâtion
Novial: Stelaro
occitan: Constellacion
oʻzbekcha/ўзбекча: Yulduz turkumi
ਪੰਜਾਬੀ: ਖਿੱਤੀਆਂ
پنجابی: تارہ چرمٹ
Piemontèis: Costelassion
Plattdüütsch: Steernbild
português: Constelação
română: Constelație
Runa Simi: Warani
русский: Созвездие
sicilianu: Custiddazzioni
Simple English: Constellation
slovenčina: Súhvezdie
slovenščina: Ozvezdje
српски / srpski: Сазвежђе
srpskohrvatski / српскохрватски: Sazviježđe
Basa Sunda: Rasi Béntang
suomi: Tähdistö
svenska: Stjärnbild
Tagalog: Konstelasyon
татарча/tatarça: Йолдызлык
тоҷикӣ: Бурҷ
Türkçe: Takımyıldız
українська: Сузір'я
ئۇيغۇرچە / Uyghurche: 12 بۇرج
Tiếng Việt: Chòm sao
walon: Stoelreye
文言: 星座
Winaray: Constelasyon
吴语: 星座
粵語: 星座
中文: 星座