Sunday, December 2, 2012


In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms (which themselves are generally referred to in non-technical language as "constellations"), which are patterns formed by prominent stars within apparent proximity to one another on Earth's night sky. Sony VAIO PCG-3B1M Battery
There are also numerous historical constellations not recognized by the IAU, or constellations recognized in regional traditions of astronomy or astrology, such as Chinese, Hindu and Australian Aboriginal.
The Late Latin term constellātiō can be translated as "set with stars". Sony VAIO PCG-3C1T Battery
The term was first used in astrology, of asterisms that supposedly exerted influence, attested in Ammianus (4th century). In English the term was used from the 14th century, also in astrology, of conjunctions of planets. The modern astronomical sense of "area of the celestial sphere around a specific asterism" dates to the mid 16th century. Sony VAIO PCG-3D1M Battery
Colloquial usage does not distinguish the senses of "asterism" and "area surrounding an asterism". The modern system of constellations used in astronomy focuses primarily on constellations as grid-like segments of the celestial sphere rather than as patterns, while the term for a star-pattern is asterism. Sony VAIO PCG-3G2M Battery
For example, the asterism known as the Big Dipper corresponds to the seven brightest stars of the larger IAU constellation ofUrsa Major.The term circumpolar constellation is used for any constellation that, from a particular latitude on Earth, never sets below the horizon. From the north pole, all constellations north of the celestial equator are circumpolar constellations. Sony VAIO PCG-5R1M Battery
In the northern latitudes, the informal term equatorial constellation has sometimes used for constellations that lie to the south of the circumpolar constellations.[1] Depending on the definition, equatorial constellations can include those that lie entirely between declinations 45° north and 45° south, or those that pass overhead between the tropics of Cancer and Capricorn.Sony VAIO PCG-7141M Battery
They generally include all constellations that intersect the celestial equator.
The current list of 88 constellations recognised by the International Astronomical Union since 1922 is based on the 48 listed by Ptolemy in his Almagest in the 2nd century. Ptolemy's catalogue is informed by Eudoxus of Cnidus, a Greek astronomer of the 4th century BC who introduced earlier Babylonian astronomy to the Hellenistic culture. Sony VAIO PCG-7143M Battery
Of the 48 constellations listed by Ptolemy, thirty can be shown to have a much longer history, reaching back into at least the Late Bronze Age. This concerns the zodiacal constellations in particular.The oldest catalogues of stars and constellations are from Old Babylonian astronomy, beginning in the Middle Bronze Age. Sony VAIO PCG-7151M Battery
The numerous Sumerian names in these catalogues suggest that they build on older, but otherwise unattested, Sumerian traditions of the Early Bronze Age. The classical Zodiac is a product of a revision of the Old Babylonian system in later Neo-Babylonian astronomy 6th century BC. Knowledge of the Neo-Babylonian zodiac is also reflected in the Hebrew Bible. Sony VAIO PCG-7154M Battery
E. W. Bullinger interpreted the creatures appearing in the books of Ezekiel (and thence in Revelation) as the middle signs of the four quarters of the Zodiac,[5][6] with the Lion as Leo, the Bull is Taurus, the Man representing Aquarius and the Eagle standing in for Scorpio. Sony VAIO PCG-7162M Battery
The biblical Book of Job (dating to the 6th to 4th century BC) also makes reference to a number of constellations, including עיש `Ayish "bier", כסיל Kĕciyl "fool" and כימה Kiymah "heap" (Job 9:9, 38:31-32), rendered as "Arcturus, Orion and Pleiades" by the KJV, but `Ayish "the bier" actually corresponding to Ursa Major. Sony VAIO PCG-7181M Battery
The term Mazzaroth מַזָּרֹות, ahapax legomenon in Job 38:32, may be the Hebrew word for the zodiacal constellations.The Greeks adopted the Babylonian system in the 4th century BC. A total of twenty Ptolemaic constellations are directly continued from the Ancient Near East. Another ten have the same stars but different names. Sony VAIO PCG-41112M Battery
There is only limited information on indigenous Greek constellations. Some evidence is found in Hesiod. Greek astronomy essentially adopted the older Babylonian system in the Hellenistic era, first introduced to Greece by Eudoxus of Cnidus in the 4th century BC. Sony VAIO PCG-7153M Battery
The original work of Eudoxus is lost, but it survives as a versification by Aratus, dating to the 3rd century BC. The most complete existing works dealing with the mythical origins of the constellations are by the Hellenistic writer termed pseudo-Eratosthenes and an early Roman writer styled pseudo-Hyginus. Sony VAIO PCG-71312M Battery
The basis of western astronomy as taught during Late Antiquity and until the Early Modern period is the Almagest by Ptolemy, written in the 2nd century. Indian astronomy is also based on Hellenistic tradition, via transmission by the Indo-Greek kingdoms.
In classical Chinese astronomy, the northern sky is divided geometrically, Sony VAIO PCG-7144M Battery
into five "enclosures" and twenty-eight mansions along the ecliptic, grouped intoFour Symbols of seven asterisms each. The 28 lunar mansions are one of the most important and also the most ancient structures in the Chinese sky, attested from the 5th century BC. Parallels to the earliest Babylonian (Sumerian) star catalogues suggest that the ancient Chinese system did not arise independently from that of the Ancient Near East. Sony VAIO PCG-7191L Battery
Classical Chinese astronomy is recorded in the Han period and appears in the form of three schools, which are attributed to astronomers of the Zhanguo period. The constellations of the three schools were conflated into a single system by Chen Zhuo, an astronomer of the 3rd century (Three Kingdoms period). Sony VAIO PCG-3C1M Battery
Chen Zhuo's work has been lost, but information on his system of constellations survives in Tang period records, notably by Qutan Xida. The oldest extant Chinese star chart dates to the Tang period and was preserved as part of the Dunhuang Manuscripts. Native Chinese astronomy flourished during the Song Dynasty, and during the Yuan Dynasty became increasingly influenced by medieval Islamic astronomy. Sony VAIO PCG-3F1M Battery
The constellations around the South Pole were not observable from north of the equator, by Babylonians, Greeks, Chinese or Arabs.The modern constellations in this region were defined during the age of exploration, notably by Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman at the end of sixteenth century. Sony VAIO PCG-3H1M Battery
They were depicted by Johann Bayer in his star atlas Uranometria of 1603. Several more were created by Nicolas Louis de Lacaille in his star catalogue, published in 1756.
Some modern proposals for new constellations were not successful; an example is Quadrans, eponymous of the Quadrantid meteors, now divided between Boötes andDraco. Sony VAIO PCG-3J1M Battery
The classical constellation of Argo Navis was broken up into several different constellations, for the convenience of stellar cartographers.By the end of the Ming Dynasty, Xu Guangqi introduced 23 asterisms of the southern sky based on the knowledge of western star charts. These asterisms have since been incorporated into the traditional Chinese star maps. Sony VAIO PCG-8141M Battery
In 1922, Henry Norris Russell aided the IAU in dividing the celestial sphere into 88 official constellations.[13] Where possible, these modern constellations usually share the names of their Graeco-Roman predecessors, such as Orion, Leo or Scorpius. The aim of this system is area-mapping, i.e. the division of the celestial sphere into contiguous fields. Sony VAIO PCG-8161M Battery
Out of the 88 modern constellations, 36 lie predominantly in the northern sky, and the other 52 predominantly in the southern.In 1930, the boundaries between the 88 constellations were devised by Eugène Delporte along vertical and horizontal lines of right ascension and declination.However, the data he used originated back to epoch B1875.0, which was when Benjamin A. Sony VAIO PCG-3C2M Battery
Gould first made the proposal to designate boundaries for the celestial sphere, a suggestion upon which Delporte would base his work. The consequence of this early date is that due to the precession of the equinoxes, the borders on a modern star map, such as epoch J2000, are already somewhat skewed and no longer perfectly vertical or horizontal. Sony VAIO PCG-5N2M Battery
This effect will increase over the years and centuries to come.
The stars of the main asterism within a constellation are usually given Greek letters in their order of brightness, the so-called Bayer designation introduced by Johann Bayer in 1603. A total of 1,564 stars are so identified, out of approximately 10,000 stars visible to the naked eye. Sony VAIO PCG-5P1M Battery
The brightest stars, usually the stars that make up the constellation's eponymous asterism, also retain proper names, often from Arabic. For example, the "Little Dipper" asterism of the constellation Ursa Minor has ten stars with Bayer designation, α UMi to π UMi. Of these ten stars, seven have a proper name, viz. Sony VAIO PCG-5S1M Battery
Polaris (α UMi),Kochab (β UMi), Pherkad (γ UMi), Yildun (δ UMi), Urodelus (ε UMi), Ahfa al Farkadain (ζ UMi) and Anwar al Farkadain (η UMi).
The stars within an asterism rarely have any substantial astrophysical relationship to each other, Sony VAIO PCG-9Z1M Battery
and their apparent proximity when viewed from Earth disguises the fact that they are far apart, some being much farther from Earth than others. However, there are some exceptions: many of the stars in the constellation of Ursa Major(including most of the Big Dipper) are genuinely close to one another, Sony VAIO PCG-7171M Battery
travel through the galaxy with similarvelocities, and are likely to have formed together as part of a cluster that is slowly dispersing. These stars form the Ursa Major moving group.
The Great Rift, a series of dark patches in the Milky Way, is more visible and striking in thesouthern hemisphere than in the northern. Sony VAIO PCG-7186M Battery
It vividly stands out when conditions are otherwise so dark that the Milky Way's central region casts shadows on the ground. Some cultures have discerned shapes in these patches and have given names to these "dark cloud constellations." Members of theInca civilization identified various dark areas or dark nebulae in the Milky Way as animals, and associated their appearance with the seasonal rains. Sony VAIO PCG-81112M Battery
Australian Aboriginal astronomy also describes dark cloud constellations, the most famous being the "emu in the sky" whose head is formed by the Coalsack.
Aries is one of the constellations of the zodiac, the groups of stars through which the apparent course of the sun passes during the year. Sony VAIO PCG-31311M Battery
It is located in the Northern Hemisphere between Pisces to the west and Taurus to the east. The name Aries is Latin for ram, and its symbol is   (Unicode ♈), representing a ram's horns. It is one of the 48 constellations described by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. Sony VAIO PCG-8152M Battery
It is a mid-sized constellation, ranking 39th overall size, with an area of 441 square degrees (1.1% of the celestial sphere).Although Aries came to represent specifically the ram whose fleece became the Golden Fleece of Ancient Greek mythology, it has represented a ram since late Babylonian times. Before that, the stars of Aries formed a farmhand. Sony VAIO PCG-31111M Battery
Different cultures have incorporated the stars of Aries into different constellations including twin inspectors in China and a porpoise in the Marshall Islands. Aries is a relatively dim constellation, possessing only four bright stars: Hamal(Alpha Arietis, second magnitude), Sheratan (Beta Arietis, third magnitude), Sony VAIO PCG-61111M Battery
Mesartim (Gamma Arietis, fourth magnitude), and 41 Arietis (also fourth magnitude). The few deep-sky objects within the constellation are quite faint and include several pairs of interacting galaxies. Several meteor showers appear to radiate from Aries, including the Daytime Arietids and the Epsilon Arietids. Sony VAIO PCG-51112M Battery
Aries is now recognized as an official constellation, albeit as a specific region of the sky, by the International Astronomical Union. It was originally defined in ancient texts as a specific pattern of stars, and has remained a constellation since ancient times; it now includes the ancient pattern as well as the surrounding stars. Sony VAIO PCG-51211M Battery
In the description of the Babylonian zodiac given in the clay tablets known as the MUL.APIN, the constellation now known as Aries was the final station along the ecliptic. The MUL.APIN was a comprehensive table of the risings and settings of stars, which likely served as an agricultural calendar. Sony VAIO PCG-51212M Battery
Modern-day Aries was known as MULLÚ.ḪUN.GÁ, "The Agrarian Worker" or "The Hired Man".[5] Although likely compiled in the 12th or 11th century BCE, the MUL.APIN reflects a tradition which marks the Pleiades as the vernal equinox, which was the case with some precision at the beginning of the Middle Bronze Age. Sony VAIO PCG-41111M Battery
The earliest identifiable reference to Aries as a distinct constellation comes from the boundary stones that date from 1350 to 1000 BCE. On several boundary stones, a zodiacal ram figure is distinct from the other characters present. Sony VAIO PCG-41111V Battery
The shift in identification from the constellation as the Agrarian Worker to the Ram likely occurred in later Babylonian tradition because of its growing association with Dumuzi the Shepherd. By the time the MUL.APIN was created—by 1000 BCE—modern Aries was identified with both Dumuzi's ram and a hired laborer. Sony VAIO PCG-61412V Battery
The exact timing of this shift is difficult to determine due to the lack of images of Aries or other ram figures.
In ancient Egyptian astronomy, Aries was associated with the god Amon-Ra, who was depicted as a man with a ram's head and represented fertility and creativity. Sony VAIO PCG-71112M Battery
Because it was the location of the vernal equinox, it was called the "Indicator of the Reborn Sun".During the times of the year when Aries was prominent, priests would process statues of Amon-Ra to temples, a practice that was modified by Persian astronomers centuries later. Aries acquired the title of "Lord of the Head" in Egypt, referring to its symbolic and mythological importance. Sony VAIO PCG-81111V Battery
Aries was not fully accepted as a constellation until classical times.[9]In Hellenistic astrology, the constellation of Aries is associated with the golden ram of Greek mythology that rescued Phrixos and Helle on orders from Hermes, taking him to the land of Colchis. Sony VAIO PCG-81111V Battery
Phrixos and Helle were the son and daughter of King Athamas and his first wifeNephele. The king's second wife, Ino, was jealous and wished to kill his children. To accomplish this, she induced a famine in Boeotia, then falsified a message from the Oracle of Delphi that said Phrixos must be sacrificed to end the famine. Sony VAIO PCG-81212M Battery
Athamas was about to sacrifice his son atopMount Laphystium when Aries, sent by Nephele, arrived.[13] Helle fell off of Aries's back in flight and drowned in the Dardanelles, also called the Hellespont in her honor. After arriving, Phrixos sacrificed the ram toZeus and gave the Fleece to Aeëtes of Colchis, who rewarded him with an engagement to his daughter Chalciope. Sony VAIO PCG-81212V Battery
Aeëtes hung its skin in a sacred place where it became known as the Golden Fleece and was guarded by a dragon. In a later myth, this Golden Fleece was stolen by Jason and the Argonauts.
Historically, Aries has been depicted as a crouched, wingless ram with its head turned towards Taurus. Sony VAIO PCG-51111M Battery
Ptolemy asserted in his Almagest that Hipparchus depictedAlpha Arietis as the ram's muzzle, though Ptolemy did not include it in his constellation figure. Instead, it was listed as an "unformed star", and denoted as "the star over the head". John Flamsteed, in his Atlas Coelestis, followed Ptolemy's description by mapping it above the figure's head. Sony VAIO VPCS13X9E/B battery
Flamsteed followed the general convention of maps by depicting Aries laying down.[7] Astrologically, Aries has been associated with the head and its humors.[15] It was strongly associated with Mars, both the planet and the god. It was considered to govern Western Europe and Syria, and to indicate a strong temper in a person.[16] Sony VAIO VPCS12V9E/B battery
The First Point of Aries, the location of the vernal equinox, is named for the constellation. This is because the Sun crossed the celestial equator from south to north in Aries more than two millennia ago. Hipparchus defined it in 130 BCE. as a point south of Gamma Arietis. Sony VAIO VPCS12V9E/B battery
Because of the precession of the equinoxes, the First Point of Aries has since moved into Pisces and will move into Aquarius by around 2600 CE. The Sun now appears in Aries from late April through mid May, though the constellation is still associated with the beginning of spring. Sony VAIO VPCF13M8E/B battery
Medieval Muslim astronomers depicted Aries in various ways. Astronomers like al-Sufi saw the constellation as a ram, modeled on the precedent of Ptolemy. However, some Islamic celestial globes depicted Aries as a nondescript four-legged animal with what may be antlers instead of horns. Sony VAIO VPCF13Z0E/B battery
Some early Bedouinobservers saw a ram elsewhere in the sky; this constellation featured the Pleiades as the ram's tail.[19] The generally accepted Arabic formation of Aries consisted of thirteen stars in a figure along with five "unformed" stars, four of which were over the animal's hindquarters and one of which was the disputed star over Aries's head. Sony VAIO VPCM13M1E/L battery
Al-Sufi's depiction differed from both other Arab astronomers' and Flamsteed's, in that his Aries was running and looking behind itself.The obsolete constellations introduced in Aries (Musca Borealis, Vespa, and Apis) have all been composed of the northern stars. Musca Borealis was created from the stars 33 Arietis, 35 Arietis, 39 Arietis, and 41 Arietis. Sony VAIO VPCM13M1E/W battery
In 1612, Petrus Plancius introduced Apis, a constellation representing a bee. In 1624, the same stars were used by Jakob Bartsch to create a constellation called Vespa, representing a wasp. Neither constellation became widely accepted. Johann Heveliusrenamed the constellation "Musca" in 1690 in his Firmamentum SobiescianumSony VAIO VPCF22M1E battery
To differentiate it from Musca, the southern fly, it was later renamed Musca Borealis but it did not gain acceptance and its stars were ultimately officially reabsorbed into Aries.[22]
In 1922, the International Astronomical Union defined its recommended three-letter abbreviation, "Ari".Sony VAIO VPCF11M1E/H battery
The official boundaries of Aries were defined in 1930 by Eugène Delporte as a polygon of 12 segments. Its right ascension is between 1h 46.4m and 3h 29.4m and its declination is between 10.36° and 31.22° in theequatorial coordinate system.
In traditional Chinese astronomy, stars from Aries were used in several constellations. Sony VAIO VPCF13M0E/B battery
The brightest stars—Alpha, Beta, and Gamma Arietis—formed a constellation called Lou, variously translated as "bond", "lasso", and "sickle", which was associated with the ritual sacrifice of cattle. This name was shared by the 16th lunar mansion, the location of the full moon closest to the autumnal equinox. Sony VAIO VPCYB2M1E battery
The lunar mansion represented the area where animals were gathered before sacrifice around that time.[13] This constellation has also been associated with harvest-time as it could represent a woman carrying a basket of food on her head.35, 39, and 41 Arietis were part of a constellation called WeiSony VAIO VPCYB3V1E battery
which represented a fat abdomen and was the namesake of the 17th lunar mansion, which represented granaries. Delta and Zeta Arietis were a part of the constellation Tianyin, thought to represent the Emperor's hunting partner. Zuogeng (Tso-kang), a constellation depicting a marsh and pond inspector, was composed of Mu, Nu, Omicron, Pi, and Sigma Arietis. Sony VAIO VPCY11M1E battery
He was accompanied by Yeou-kang, a constellation depicting an official in charge of pasture distribution.[7]
In a similar system to the Chinese, the first lunar mansion in Hindu astronomy was called "Aswini", after the traditional names for Beta and Gamma Arietis, theAswins. Sony VAIO VPCS12L9E/B battery
Because the Hindu new year began with the vernal equinox, the Rig Veda contains over 50 new-year's related hymns to the twins, making them some of the most prominent characters in the work. Aries itself was known as "Aja" and "Mesha".[16] In Hebrew astronomy Aries was named "Teli";Sony VAIO VPCF11S1E/B battery
it signified either Simeon orGad, and generally symbolizes the "Lamb of the World". The neighboring Syrians named the constellation "Amru", and the bordering Turks named it "Kuzi".[16] Half a world away, in the Marshall Islands, several stars from Aries were incorporated into a constellation depicting a porpoise, Sony VAIO VPCYB3V1E/R Battery
along with stars from Cassiopeia,Andromeda, and Triangulum. Alpha, Beta, and Gamma Arietis formed the head of the porpoise, while stars from Andromeda formed the body and the bright stars of Cassiopeia formed the tail.[24] Other Polynesian peoples recognized Aries as a constellation. Sony VAIO VPCF23P1E Battery

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