Also, the "English translation" isn't usually used by English speakers. Latin names are standard English usage. The zodiacal signs are distinct 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 take up varying widths of the ecliptic, so the Sun is not in each constellation for the same amount of time.
The zodiacal signs are an abstraction from the physical constellations, and each represent exactly one 12th of the full circle, or the longitude traversed by the Sun in about The path of the Sun passes through 13 constellations recognized by ancient Babylonian, Greek, and Roman astronomers including in Ptolemy 's Almagest   and the modern International Astronomical Union.
Because the Babylonians had a month lunar calendar, they chose and divided up the year evenly. The 13th was left out: Ophiuchus , the bottom part of which interjects between Scorpio and Sagittarius. Occasionally this difference between the astronomical constellations and the astrological signs is mistakenly reported in the popular press as a "change" to the list of traditional signs by some astronomical body like the IAU, NASA , or the Royal Astronomical Society.
For example, in drawing a distinction between astrology and scientific astronomy, NASA notes that "No one has shown that astrology can be used to predict the future or describe what people are like based on their birth dates. Some "parazodiacal" constellations are also touched by the paths of the planets, leading to counts of up to 25 "constellations of the zodiac". Some other constellations are also 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. The following table compares the Gregorian dates on which the Sun enters:. 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.
Except for and , the vernal equinox has started on 20 March since , and is projected to until Because the Earth's axis is at an angle, some signs take longer to rise than others, and the farther away from the equator the observer is situated, the greater the difference. Thus, signs are spoken of as "long" or "short" ascension.
The zodiac system was developed in Babylonia , some 2, years ago, during the " Age of Aries ". Contemporary use of the coordinate system is presented with the choice of interpreting the system either as sidereal , with the signs fixed to the stellar background , or as tropical , with the signs fixed to the point vector of the Sun at the March equinox.
Western astrology takes the tropical approach, whereas Hindu astrology takes the sidereal one. This results in the originally unified zodiacal coordinate system drifting apart gradually, with a clockwise westward precession of 1. For the tropical zodiac used in Western astronomy and astrology, this means that the tropical sign of Aries currently lies somewhere within the constellation Pisces " Age of Pisces ". The sidereal coordinate system takes into account the ayanamsa , ayan meaning transit or movement , and amsa meaning small part , i.
It is unclear when Indians became aware of the precession of the equinoxes, but Bhaskara 2 's 12th-century treatise Siddhanta Shiromani gives equations for measurement of precession of equinoxes, and says his equations are based on some lost equations of Suryasiddhanta plus the equation of Munjaala. The discovery of precession is attributed to Hipparchus around BC.
Ptolemy quotes from Hipparchus' now lost work entitled "On the Displacement of the Solstitial and Equinoctial Points" in the seventh book of his 2nd century astronomical text, Almagest , where he describes the phenomenon of precession and estimates its value. The principle of the vernal point acting as the first degree of the zodiac for Greek astronomers is also described in the 1st century BC astronomical text of Geminus of Rhodes.
Geminus explains that Greek astronomers of his era associate the first degrees of the zodiac signs with the two solstices and the two equinoxes, in contrast to the older Chaldean Babylonian system, which placed these points within the zodiac signs. Ptolemy also demonstrates that the principle of the tropical zodiac was well known to his predecessors within his astrological text, the Tetrabiblos , where he explains why it would be an error to associate the regularly spaced signs of the seasonally aligned zodiac with the irregular boundaries of the visible constellations:.
These events can be useful, for example, to estimate the cross-sectional dimensions of a minor planet , or check a star for a close companion. The Sun's placement upon the vernal equinox, which occurs annually around 21 March, defines the starting point for measurement, the first degree of which is historically known as the " first point of Aries ". Zodiac signs have never been used to determine the boundaries of astronomical constellations that lie in the vicinity of the zodiac, which are, and always have been, irregular in their size and shape. The use of the zodiac as a means to determine astronomical measurement remained the main method for defining celestial positions by Western astronomers until the Renaissance, at which time preference moved to the equatorial coordinate system , which measures astronomical positions by right ascension and declination rather than the ecliptic-based definitions of celestial longitude and celestial latitude.
The word "zodiac" is also used in reference to the zodiacal cloud of dust grains that move among the planets, and the zodiacal light that originates from their scattering of sunlight. In Unicode, the symbols of zodiac signs are encoded in block "Miscellaneous Symbols": . From Wikipedia, the free encyclopedia. This is the latest accepted revision , reviewed on 5 October For the East Asian zodiac based on the Jovian orbital cycle, see Chinese zodiac. For other uses, see zodiac disambiguation. Further information: Former constellations.
Further information: Babylonian star catalogues and MUL. Main article: Astrological sign. Further information: Axial precession , Epoch astronomy , Sidereal and tropical astrology , Astrological age , and Ayanamsa. Astronomical symbols Chinese zodiac Circle of stars Cusp astrology Elements of the zodiac. Oxford Dictionaries. Oxford University Press. Retrieved 19 September The Signs of the Zodiac. Wilcox, London, p. See also Lankford, John; Rothenberg, Marc History of Astronomy: An Encyclopedia. The Almagest. Translated and annotated by G.
Toomer ; with a foreword by Owen Gingerich.
The introduction of the uniform zodiac", Archive for History of Exact Sciences , 64 6 : —, doi : The Mesopotamian traditions. Astronomical Data Service.
Page Lennart Geminos's Introduction to the Phenomena. Princeton University Press.
Ptolemy's Tetrabiblos. Astrology Classics. Project Hindsight. Retrieved 4 July Hinduism: An Alphabetical Guide. Penguin Books India. London: Board of Longitude, Patrick Grim ed. Philosophy of science and the occult.
Ptolemy's Catalogue of Stars: a revision of the Almagest. Carnegie Institution of Washington, Catesby Taliaferro ed.
Ptolemy refers to the constellation as Septentarius "the serpent holder". October The Observatory. They are considered reformers, but can be cold and indifferent. They are often eccentric, erratic, rebellious, unpredictable, highly opinionated, original, one-of-a-kind, friendly, sharp-tongued, idealistic, inventive, quick to change their minds, and resolute.
Learn Pisces traits. Independent, determined and innovative. They are highly creative, smart, passionate, sensitive and friendly. They like to take care of others, but are often viewed as offensive because of their changing temperaments. Examine their appearance.
Each sign has several physical attributes commonly associated with it. Look at the person carefully and see if any of the following descriptions are true for them.
What strikes you most about how they look? Usually the ascendant influences the physical appearance more dominantly so you may be able to guess that using physical traits and not the sun sign which is the typical zodiac determined by your birth date alone. Learn the physical traits of Aries. These traits include high set and narrow facial bones, broad foreheads, rosy cheeks, strong, well-proportioned body, above or below average height, and dark or sandy colored hair, strong eyebrows not necessarily large though, they're often extremely thin but very notable , as well as clear and penetrating eyes which are often close-set.
Learn the physical traits of Taurus.
Taurus is ruled by Venus so these people will often be very attractive overall. Their bodies tend to be quite square overall. They typically have low foreheads, slightly thicker than usual necks, and attractive faces. They hold a steady eye contact which feels comforting instead of alarming. It always seems like their eyes are there to help you. Learn the physical traits of Gemini. A mischievous smile , full lips, average height, and a well-proportioned chin are standard characteristics of Geminis.
They usually have high cheekbones and a youthful appearance, often large eyes.