Zodiac

Zodiac In astronomy, the zodiac is the ring of constellations that lines the ecliptic, which is the apparent path of the Sun across the sky over the course of the year. The Moon and planetsalso lie within the ecliptic, and so are also within the constellations of the zodiac. In astrology, the zodiac denotes those signs which divide the ecliptic into twelve equal zones of celestial longitude. As such, the zodiac is a celestial coordinate system, more precisely an ecliptic coordinate system, taking the ecliptic as the origin of latitude, and the position of the sun atvernal equinox as the origin of longitude. It is known to have been in use by the Roman era, based on concepts inherited by Hellenistic astronomy from Babylonian astronomy of the Chaldean period (mid 1st millennium BC), which in turn derived from an earlier system of lists of stars along the ecliptic.[1] The construction of the zodiac is described in Ptolemy's Almagest (2nd century AD). The term zodiac may also refer to the region of the celestial sphere encompassing the paths of the Moon and the planets corresponding to the band of about eight arc degrees above and below the ecliptic. The zodiac of a given planet is the band which contains the path of that particular body, e.g. the "zodiac of the Moon" is the band of five degrees above and below the ecliptic. By extension, the "zodiac of the comets" may refer to the band encompassing mostshort-period comets [2] The term zodiac derives from Latin zōdiacus, in turn from the Greek ζωδιακός κύκλος(zōdiakos kuklos), meaning "circle of animals", derived from ζώδιον (zōdion), the diminutive ofζῶον (zōon) "animal". The name is motivated by the fact that many of the signs of the classical Greek zodiac are represented as animals (six out of twelve, plus two mythological hybrids). Although the zodiac remains the basis of the ecliptic coordinate system in use in astronomybesides the equatorial one, the term and the names of the twelve signs are today mostly associated with horoscopic astrology. Wheel of the zodiac: This 6th century mosaic pavement in a synagogue incorporates Greek-Byzantine elements, Beit Alpha, Israel The Earth in its orbit around the Sun causes the Sun to appear on the celestial sphere moving over the ecliptic (red), which is tilted on the equator (blue). History The 1st century BC Denderah Zodiac (19th-century engraving) Further information: Babylonian zodiac, History of astronomy, and History of astrology The division of the ecliptic into the zodiacal signs originates in Babylonian ("Chaldean") astronomy during the first half of the 1st millennium BC, likely during Median/"Neo-Babylonian" times (7th century BC)[3], continuing earlier (Bronze Age) systems of lists of stars. Babylonian astronomers at some point during the early 1st millennium BC divided the ecliptic into twelve equal zones of celestial longitude to create the first known celestial coordinate system: a coordinate system that boasts some advantages over modern systems (such as equatorial coordinate system or ecliptic coordinate system). The Babylonian calendar as it stood in the 7th century BC assigns each month a constellation, beginning with the position of the Sun at vernal equinox, which at the time was the Aries constellation ("Age of Aries"), for which reason the first astrological sign is still called "Aries" even after the vernal equinox has moved away from the Aries constellation. However, a scientific analysis of the location of the constellations suggest their determination in this region in the Bronze Age (~2700 BC),[4][5] thereby suggesting an earlier establishment of the constellations. The Babylonian zodiac also finds reflection in the Hebrew Bible. The name of the twelve signs are equivalent to the names in use today, except that the name of the Eagle seems to have been usually substituted for Scorpio. [6][7] The arrangement of the twelve tribes of Israel around the Tabernacle (Numbers 2) corresponded to the order of the Zodiac; and four of the tribes represented the middle signs of each quarter: Judah was the Lion, Reuben the Man, Ephraimthe Bull, and Dan the Eagle. [8][9][10] Thomas Mann in Joseph and His Brothers takes theBlessing of Jacob as attributing characteristics of a sign of the zodiac to each tribe. The faces of the cherubim, in both Ezekiel and Revelation, are the middle signs of the four quarters of the Zodiac: the Lion is Leo; the Bull is Taurus; the Man is Aquarius; and the Eagle is Scorpio.[citation needed] A 17th-century Christian fresco from the Cathedral of Living Pillar in Georgia depictingChrist within the Zodiac circle Hellenistic astrology was a syncretism of Babylonian and Egyptian astrology, and it was inPtolemaic Egypt where horoscopic astrology first appeared. The Dendera zodiac, a relief dating to ca. 50 BC, is the first known depiction of the classical zodiac of twelve signs. Babylonia or Chaldea in the Hellenistic world came to be so identified with astrology that "Chaldean wisdom" became among Greeks and Romans the synonym of divination through the planets and stars. The Hindu zodiac is a direct loan of the Greek system, adopted during the period of intenseIndo-Greek cultural contact during the Seleucid period (2nd to 1st centuries BC). In Hindu astrology, the individual signs are called 'rāshi. The transmission of the zodiac system to Hindu astrology predated widespread awareness of the precession of the equinoxes, and the Hindu system ended up using a sidereal coordinate system, which resulted in the European and the Hindu zodiacs, even though sharing the same origin in Hellenistic astrology, gradually moving apart over two millennia that have passed since. The Sanskrit names of the signs are direct translations of the Greek names (dhanus meaning "bow" rather than "archer", and kumbha meaning "water-pitcher" rather than "water-carrier"). Particularly important in the development of horoscopic astrology was the astrologer and astronomer Ptolemy, whose work, the Tetrabiblos laid the basis of the Western astrological tradition. Under the Greeks and Ptolemy in particular, the planets, Houses, and signs of the zodiac were rationalized and their function set down in a way that has changed little to the present day.[11] Ptolemy lived in the 2nd century AD, three centuries after the discovery of theprecession of the equinoxes by Hipparchus around 130 BC, but he ignored the problem, apparently by dropping the concept of a fixed celestial sphere and adopting what is referred to as a tropical coordinate system instead. The zodiac signs as shown in a 16th century woodcut The High Middle Ages saw a revival of Greco-Roman magic, first in Kabbalism and later continued in Renaissance magic. This included magical uses of the zodiac, as found e.g. in the Sefer Raziel HaMalakh. The zodiacal signs remain in use as the basis of an ecliptic coordinate system, though modern astronomers tend to use an equatorial coordinate system since Early Modern times. One can see the use of the sidereal coordinate remained in use throughout the medieval period, e.g. in Hermannus Contractus in his de mensura astrolabii liber who gives the locations of stars in stereographic projection for the construction of an astrolabe, There he gives the zodiac coordinate of Antares as 14. Scorpius, equalling a J2000.0 ecliptic longitude of 224° (the 14th degree from the beginning of Scorpius at 210°). The twelve signs The symbols used in Western astrology to represent the astrological signs Main article: Astrological sign What follows is a list of the twelve signs of the zodiac (with the ecliptic longitudes of their first points), where 0° Aries is understood as the vernal equinox, with their Latin, Greek, Sanskrit and Babylonian names (but note that the Sanskrit and the Babylonian name equivalents denote the constellations only, not the tropical zodiac signs): no. symbol long. Latin name English translation Greek name Sanskrit name Sumero-Babylonian name[12] 1 ♈ 0° Aries The Ox Κριός Meṣa MUL LUḪUN.GA "The Agrarian Worker", Dumuzi 2 ♉ 30° Taurus The Bull Ταύρος Vṛṣabha MULGU4.AN.NA "The Steer of Heaven" 3 ♊ 60° Gemini The Twins Δίδυμοι Mithuna MULMAŠ.TAB.BA.GAL.GAL"The Great Twins" (Lugalgirra and Meslamta-ea) 4 ♋ 90° Cancer The Crab Καρκίνος Karka MULAL.LUL "The Crayfish" 5 ♌ 120° Leo The Lion Λέων Siṃha MULUR.GU.LA "The Lion" 6 ♍ 150° Virgo The Virgin Παρθένος Kanyā MULAB.SIN "The Furrow"; "The Furrow, the goddess Shala's ear of corn" 7 ♎ 180° Libra The Scales Ζυγός Tula zibanitum "The Scales" 8 ♏ 210° Scorpio The Scorpion Σκoρπιός Vṛścika MULGIR.TAB "The Scorpion" 9 ♐ 240° Sagittarius Centaur The Archer Τοξότης Dhanus MULPA..BIL.SAG, Nedu"soldier" 10 ♑ 270° Capricorn "Goat-horned" (The Sea-Goat) Αἰγόκερως Makara MULSUḪUR.MAŠ "The Goat-Fish" 11 ♒ 300° Aquarius The Water Bearer Ὑδροχόος Kumbha MULGU.LA "The Great One", later qâ "pitcher" 12 ♓ 330° Pisces The Fishes Ἰχθείς Mīna MULSIM.MAḪ "The Tail of the Swallow", later DU.NU.NU "fish-cord" The zodiacal symbols are Early Modern simplifications of conventional pictorial representations of the signs, attested since Hellenistic times.. The symbols are encoded inUnicode at positions U+2648 to U+2653 Zodiacal constellations It is important to distinguish the zodiacal signs from the constellations associated with them, not only because of their drifting apart due to the precession of equinoxes but also because the physical constellations by nature of their varying shapes and forms take up varying widths of the ecliptic. Thus, Virgo takes up fully five times as much ecliptic longitude as Scorpius. The zodiacal signs, on the other hand, are an abstraction from the physical constellations designed to represent exactly one twelfth of the full circle each, or the longitude traversed by the Sun in about 30.4 days.[13] There have always been a number of "parazodiacal" constellations which are also touched by the paths of the planets. The MUL.APIN lists Orion, Perseus, Auriga and Andromeda. Furthermore, there are a number of constellations mythologically associated with the zodiacal ones: Piscis Austrinus, The Southern Fish, is attached to Aquarius. In classical maps it swallows the stream poured out of Aquarius' pitcher, but perhaps it formerly just swam in it.Aquila, The Eagle, was possibly associated with the zodiac by virtue of its main star, Altair.Hydra in the Early Bronze Age marked the celestial equator and was associated with Leo, which is shown standing on the serpent on the Dendera zodiac. Corvus is the Crow or Raven mysteriously perched on the tail of Hydra.. The MUL.APIN glosses Hydra as "the SnakeNingizzida, lord of the Netherworld". Ningizzida together with Dumuzi (Aries) and Pabilsag (Sagittarius) governed the household of the queen of the underworld. Taking the current constellation boundaries as defined in 1930 by the International Astronomical Union, the ecliptic itself passes through an additional thirteenth constellation,Ophiuchus, situated between Scorpius and Sagittarius. This is already recognized inPtolemy's Almagest.[citation needed] Table of dates The following table compares the Gregorian dates on which the Sun enters a sign in the Ptolemaic tropical zodiac; a sign in the Hindu sidereal system the astronomical constellation of the same name as the sign, with constellation boundaries as defined in 1930 by the International Astronomical Union. The theoretical beginning of Aries is the moment of vernal equinox, and all other dates shift accordingly. The precise Gregorian times and dates vary slightly from year to year as the Gregorian calendar shifts relative to the tropical year.[14] These variations remain within less than two days' difference in the recent past and the near future, vernal equinox in UTC always falling either on 20 or 21 of March in the period of 1797 to 2043, falling on 19 March in 1796 the last time and in 2044 the next.[15] In the long term, if the Gregorian calendar isn't reformed, the equinox will move to earlier dates: it will fall on 18 March for the first time in AD 4092. Sign Constellation[16][17] Name Symbol Tropical zodiac (2009,UTC) Sidereal zodiac (Jyotisha) (2009,UTC)[18] Name IAU constellation boundaries (2009) Solar stay Brightest star Aries 20 March – 19 April 14 April – 14 May Aries 18 April – 14 May 25.5 days Hamal Taurus 19 April – 20 May 14 May – 13 June Taurus 14 May – 21 June 38.2 days Aldebaran Gemini 20 May – 21 June 13 June – 14 July Gemini 21 June – 20 July 29.3 days Pollux Cancer 21 June – 22 July 14 July – 13 August Cancer 20 July – 10 August 21.1 days Al Tarf Leo 22 July – 23 August 13 August – 13 September Leo 10 August – 16 September 36.9 days Regulus Virgo 23 August – 22 September 13 September – 13 October Virgo 16 September – 31 October 44.5 days Spica Libra 22 September – 23 October 13 October – 12 November Libra 31 October – 21 November 21.1 days Zubeneschamali Scorpio 23 October – 22 November 13 November – 13 December Scorpius 21 November – 29 November 8.4 days Antares Serpentarius n/a Ophiuchus 29 November – 18 December 18.4 days Rasalhague Sagittarius 22 November – 21 December 13 December – 12 January Sagittarius 18 December – 20 January 33.6 days Kaus Australis Capricorn 21 December – 20 January 12 January – 12 February Capricornus 20 January – 17 February 27.4 days Deneb Algedi Aquarius 20 January – 18 February 12 February – 14 March Aquarius 17 February – 13 March 23.9 days Sadalsuud Pisces 18 February – 20 March 14 March – 14 April Pisces 13 March – 19 April 37.7 days Eta Piscium Precession of the equinoxes Further information: Precession of the equinoxes, Epoch (astronomy), Sidereal astrology, Tropical astrology, Astrological age, and Ayanamsa path taken by the point of vernal equinox along the ecliptic over the past 6000 years The zodiac system was developed in Babylonia, some 2,500 years ago, during the "Age of Aries". At the time, the precession of the equinoxes was unknown, and the system made no allowance for it. Contemporary use of the coordinate system is presented with the choice of either interpreting the system as sidereal, with the signs fixed to the stellar background, or astropical, with the signs fixed to the point of vernal equinox. Western astrology takes the tropical approach, while Hindu astrology takes the sidereal one. This results in the originally unified zodiacal coordinate system drifting apart gradually, with an angular velocity of about 1.4 degrees per century. For the tropical zodiac used in Western astronomy and astrology, this means that the tropicalsign of Aries currently lies somewhere within the constellation Pisces ("Age of Pisces"). The choice of origin for the sidereal coordinate system is known as the ayanamsa, a Sanskrit word. It is not entirely clear how the Hellenistic astronomers responded to this phenomenon of precession once it had been discovered by Hipparchus around 130 BC. Today, some readPtolemy as dropping the concept of a fixed celestial sphere and adopting what is referred to as a tropical coordinate system instead: in other words, one fixed to the Earth's seasonal cycle rather than the distant stars. Some modern Western astrologers, such as Cyril Fagan, have advocated abandoning the tropical system in favour of a sidereal one. In modern astronomy Further information: Epoch (astronomy) The zodiac is a spherical celestial coordinate system. It designates the ecliptic as its fundamental plane and the position of the Sun at Vernal equinox as its prime meridian. In astronomy, the zodiacal constellations are a convenient way of marking the ecliptic (the Sun's path across the sky) and the path of the moon and planets along the ecliptic. Modern astronomy still uses tropical coordinates for predicting the positions the Sun, Moon, and planets, except longitude in the ecliptic coordinate system is numbered from 0° to 360°, not 0° to 30° within each sign. Longitude within individual signs was still being used as late as 1740 by Jacques Cassini in his Tables astronomiques.. Unlike the zodiac signs in astrology, which are all thirty degrees in length, the astronomical constellations vary widely in size. The boundaries of all the constellations in the sky were set by the International Astronomical Union (IAU) in 1930. This was essentially a mapping exercise to make the work of astronomers more efficient, and the boundaries of the constellations are not therefore in any meaningful sense an 'equivalent' to the zodiac signs. Along with the twelve original constellations, the boundaries of a thirteenth constellation,Ophiuchus (the serpent bearer), were set by astronomers within the bounds of the zodiac. Mnemonics for the zodiac A traditional mnemonic:[19] The Ox, the Bull, the Heavenly Twins, And next the Crab, the Lion shines, The Virgin and the Scales. The Scorpion, Archer, and the Goat, The Man who holds the Watering Pot, And Fish with glittering scales. A less poetic, but succinct and perhaps more memorable, mnemonic is the following:[20] The Ramble Twins Crab Liverish; Scaly Scorpions Are Good Water Fish. (Ox-Ble = Ox, Bull; Twins = Twins; Crab = Crab; Li-Ver(ish) = Lion, Virgin; Scaly = Scale; Scorpion = Scorpio; Are = Archer; Good = Goat; Water = Water Bearer; Fish = Fish)