The examples and perspective in this article may not represent a worldwide view of the subject.(July 2012) |
Constellation families are collections of constellations sharing some defining characteristic, such as proximity on the celestial sphere, common historical origin, or common mythological theme. In the Western tradition, most of the northern constellations stem from Ptolemy's list in the Almagest (which in turn has roots that go back to Mesopotamian astronomy), and most of the far southern constellations were introduced by sailors and astronomers who traveled to the south in the 16th to 18th centuries. Separate traditions arose in India and China.
Entirely northern:
| Primarily northern:
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Straddling ecliptic:
| Split between north and south:
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Entirely southern:
| Primarily southern:
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Donald H. Menzel, director of the Harvard Observatory, gathered several traditional groups in his popular account, A Field Guide to the Stars and Planets (1975), [1] and adjusted and regularized them so that his handful of groups covered all 88 of the modern constellations.
Of these families, one (Zodiac) straddles the ecliptic which divides the sky into north and south; one (Hercules) has nearly equal portions in the north and south; two are primarily in one hemisphere (Heavenly Waters in the south and Perseus in the north); and four are entirely in one hemisphere (La Caille, Bayer, and Orion in the south and Ursa Major in the north).
The Ursa Major Family includes 10 northern constellations in the vicinity of Ursa Major: Ursa Major itself, Ursa Minor, Draco, Canes Venatici, Boötes, Coma Berenices, Corona Borealis, Camelopardalis, Lynx, and Leo Minor. The eponymous constellation Ursa Major contains the famous Big Dipper.
The Zodiac is a group of 12 constellations: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Sagittarius, Capricornus, Aquarius, Pisces. Some version of these constellations are found in traditions around the world, for this band around the celestial sphere includes the ecliptic, the apparent path of the sun through the year. These constellations therefore are all associated with zodiac signs. (The ecliptic also passes through the constellation Ophiuchus, which does not have an associated zodiac sign.)
The Perseus Family includes several constellations associated with the Perseus myth: Cassiopeia, Cepheus, Andromeda, Perseus, Pegasus, and Cetus (representing the monster sent to devour Andromeda). Menzel also included a few neighboring constellations: Auriga, Lacerta, and Triangulum. Except for Cetus, these constellations all lie north of the ecliptic. The group reaches from near the north celestial pole to declination −30°.
The Hercules Family is a group of constellations connected mainly by their adjacency on the celestial sphere. It is Menzel's largest grouping, and extends from declination +60° to −70°, mostly in the western hemisphere. It includes Hercules, Sagitta, Aquila, Lyra, Cygnus, Vulpecula, Hydra, Sextans, Crater, Corvus, Ophiuchus, Serpens, Scutum, Centaurus, Lupus, Corona Australis, Ara, Triangulum Australe, and Crux.
The Orion Family, on the opposite side of the sky from the Hercules Family, includes Orion, Canis Major, Canis Minor, Lepus, and Monoceros. This group of constellations draws from Greek myth, representing the hunter (Orion) and his two dogs (Canis Major and Canis Minor) chasing the hare (Lepus). Menzel added the unicorn (Monoceros) for completeness.
The Heavenly Waters draws from the Mesopotamian tradition associating the dim area between Sagittarius and Orion with the god Ea and the Waters of the Abyss. [2] Aquarius and Capricornus, derived from Mesopotamian constellations, would have been natural members had they not already been assigned to the Zodiac group. Instead, Menzel expanded the area and included several disparate constellations, most associated with water in some form: Delphinus, Equuleus, Eridanus, Piscis Austrinus, Carina, Puppis, Vela, Pyxis, and Columba. Carina, Puppis, and Vela historically formed part of the former constellation Argo Navis, which in Greek tradition represented the ship of Jason.
The Bayer Family collects several southern constellations first introduced by Petrus Plancius on several celestial globes in the late 16th century, based on astronomical observations by the Dutch explorers Pieter Dirkszoon Keyser and Frederick de Houtman. The constellations were named mostly for exotic animals reported in the travel journals of that period, and were copied in Johann Bayer's influential celestial atlas Uranometria in 1603. The group includes Hydrus, Dorado, Volans, Apus, Pavo, Grus, Phoenix, Tucana, Indus, Chamaeleon, and Musca. Bayer labeled Musca as "Apis" (the Bee), but over time it was renamed. (Bayer's twelfth new southern constellation, Triangulum Australe, was placed by Menzel in the Hercules Family.) The Bayer Family circles the south celestial pole, forming an irregular contiguous band. Because these constellations are located in the far southern sky, their stars were not visible to the ancient Greeks and Romans.
The La Caille Family comprises 12 of the 13 constellations introduced by Nicolas-Louis de Lacaille in 1756 to represent scientific instruments, together with Mensa, which commemorates Table Mountain ("Mons Mensa") in South Africa, where he set up his telescope. The group includes Norma, Circinus, Telescopium, Microscopium, Sculptor, Fornax, Caelum, Horologium, Octans, Mensa, Reticulum, Pictor, and Antlia. These dim constellations are scattered throughout the far southern sky, and their stars were mostly not visible to the ancient Greeks and Romans. (Menzel assigned Pyxis, the remaining Lacaille instrument, to the Heavenly Waters group.)
Argo Navis, or simply Argo, is one of the 48 Ptolemy's constellations, now a grouping of three IAU constellations. It is formerly a single large constellation in the southern sky. The genitive is "Argus Navis", abbreviated "Arg". Flamsteed and other early modern astronomers called it Navis, genitive "Navis", abbreviated "Nav".
A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
A Flamsteed designation is a combination of a number and constellation name that uniquely identifies most naked eye stars in the modern constellations visible from southern England. They are named for John Flamsteed who first used them while compiling his Historia Coelestis Britannica.
Octans is a faint constellation located in the deep Southern Sky. Its name is Latin for the eighth part of a circle, but it is named after the octant, a navigational instrument. Devised by French astronomer Nicolas Louis de Lacaille in 1752, Octans remains one of the 88 modern constellations. The southern celestial pole is located within the boundaries of Octans.
Taurus is one of the constellations of the zodiac and is located in the northern celestial hemisphere. Taurus is a large and prominent constellation in the Northern Hemisphere's winter sky. It is one of the oldest constellations, dating back to the Early Bronze Age at least, when it marked the location of the Sun during the spring equinox. Its importance to the agricultural calendar influenced various bull figures in the mythologies of Ancient Sumer, Akkad, Assyria, Babylon, Egypt, Greece, and Rome. Its old astronomical symbol is (♉︎), which resembles a bull's head.
Triangulum is a small constellation in the northern sky. Its name is Latin for "triangle", derived from its three brightest stars, which form a long and narrow triangle. Known to the ancient Babylonians and Greeks, Triangulum was one of the 48 constellations listed by the 2nd century astronomer Ptolemy. The celestial cartographers Johann Bayer and John Flamsteed catalogued the constellation's stars, giving six of them Bayer designations.
The zodiac is a belt-shaped region of the sky that extends approximately 8° north and south of the ecliptic, which is the apparent path of the Sun across the celestial sphere over the course of the year. The orbital paths of the Moon and major planets are within the belt of the zodiac.
Traditional Chinese astronomy has a system of dividing the celestial sphere into asterisms or constellations, known as "officials".
The first point of Aries, also known as the cusp of Aries, is the location of the vernal equinox, used as a reference point in celestial coordinate systems. In diagrams using such coordinate systems, it is often indicated with the symbol ♈︎. Named for the constellation of Aries, it is one of the two points on the celestial sphere at which the celestial equator crosses the ecliptic, the other being the first point of Libra, located exactly 180° from it. Due to precession of the equinoxes since the positions were originally named in antiquity, the position of the Sun when at the vernal equinox is now in Pisces; when it is at the Autumnal equinox, it is in Virgo.
The Ox is the second of the 12-year periodic sequence (cycle) of animals which appear in the Chinese zodiac related to the Chinese calendar, and also appears in related calendar systems. The Chinese term translated here as ox is in Chinese niú , a word generally referring to cows, bulls, or neutered types of the bovine family, such as common cattle or water buffalo. The zodiacal ox may be construed as male, female, neutered, hermaphroditic, and either singular or plural. The Year of the Ox is also denoted by the Earthly Branch symbol chǒu. The term "zodiac" ultimately derives from an Ancient Greek term referring to a "circle of little animals". There are also a yearly month of the ox and a daily hour of the ox. Years of the oxen (cows) are cyclically differentiated by correlation to the Heavenly Stems cycle, resulting in a repeating cycle of five years of the ox/cow, each ox/cow year also being associated with one of the Chinese wǔxíng, also known as the "five elements", or "phases": the "Five Phases" being Fire, Water, Wood, Metal, and Earth. The Year of the Ox follows after the Year of the Rat which happened in 2020 and is then followed by the Year of the Tiger, which happened in 2022.
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 they cover the celestial sphere, with their boundaries adopted officially by the International Astronomical Union in 1928 and published in 1930.
Astronomical symbols are abstract pictorial symbols used to represent astronomical objects, theoretical constructs and observational events in European astronomy. The earliest forms of these symbols appear in Greek papyrus texts of late antiquity. The Byzantine codices in which many Greek papyrus texts were preserved continued and extended the inventory of astronomical symbols. New symbols have been invented to represent many planets and minor planets discovered in the 18th to the 21st centuries.
An asterism is an observed pattern or group of stars in the sky. Asterisms can be any identified pattern or group of stars, and therefore are a more general concept than the 88 formally defined constellations. Constellations are based on asterisms, but unlike asterisms, constellations outline and today completely divide the sky and all its celestial objects into regions around their central asterisms. For example, the asterism known as the Big Dipper comprises the seven brightest stars in the constellation Ursa Major. Another is the asterism of the Southern Cross, within the constellation of Crux.
The Catasterismi or Catasterisms, is a lost work attributed to Eratosthenes of Cyrene. It was a comprehensive compendium of astral mythology including origin myths of the stars and constellations. Only a summary of the original work survives, called the Epitome Catasterismorum, by an unknown author sometimes referred to as pseudo-Eratosthenes.
The following outline is provided as an overview of and topical guide to astronomy:
Chinese star names are named according to ancient Chinese astronomy and astrology. The sky is divided into star mansions and asterisms. The system of 283 asterisms under Three Enclosures and Twenty-eight Mansions was established by Chen Zhuo of the Three Kingdoms period, who synthesized ancient constellations and the asterisms created by early astronomers Shi Shen, Gan De and Wuxian. Since the Han and Jin Dynasties, stars have been given reference numbers within their asterisms in a system similar to the Bayer or Flamsteed designations, so that individual stars can be identified. For example, Deneb is referred to as 天津四.
Babylonian astronomy collated earlier observations and divinations into sets of Babylonian star catalogues, during and after the Kassite rule over Babylonia. These star catalogues, written in cuneiform script, contained lists of constellations, individual stars, and planets. The constellations were probably collected from various other sources. The earliest catalogue, Three Stars Each, mentions stars of Akkad, of Amurru, of Elam and others. Various sources have theorized a Sumerian origin for these Babylonian constellations, but an Elamite origin has also been proposed. A connection to the star symbology of Kassite kudurru border stones has also been claimed, but whether such kudurrus really represented constellations and astronomical information aside from the use of the symbols remains unclear.
Gould designations for stars are similar to Flamsteed designations in the way that they number stars within a constellation in increasing order of right ascension. Each star is assigned an integer, followed by " G. ", and then the Latin genitive of the constellation it lies in. See 88 modern constellations for a list of constellations and the genitive forms of their names.
This table lists those stars/objects which have Flamsteed designations by the constellation in which those stars/objects lie. The name given is that of the article if it does not reflect the Flamsteed designation. Some articles are linked twice, in cases where the star has been assigned two different Flamsteed designations, usually as noted in different constellations.
Urania's Mirror; or, a view of the Heavens is a set of 32 astronomical star chart cards, first published in November 1824. They are illustrations based on Alexander Jamieson's A Celestial Atlas, but the addition of holes punched in them allow them to be held up to a light to see a depiction of the constellation's stars. They were engraved by Sidney Hall, and were said to be designed by "a lady", but have since been identified as the work of the Reverend Richard Rouse Bloxam, an assistant master at Rugby School.