An example of the use of signs as astronomical coordinates may be found in the Nautical Almanac and Astronomical Ephemeris for the year The "Longitude of the Sun" columns show the sign represented as a digit from 0 to and including 11 , degrees from 0 to 29, minutes, and seconds. The zodiac symbols are Early Modern simplifications of conventional pictorial representations of the signs, attested since Hellenistic times. But note that the Sanskrit and the name equivalents after c. 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 ".
December 13 Birthday Horoscope
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, Birthday Horoscope December 20th, personal asctrological characteristic for those who were born on December 20th. Birthday Horoscope December 21st, personal asctrological characteristic for those who were born on December 21st. Birthday Horoscope for those who were born on December 13th under the Zodiac sign Sagittarius. December 13th Persona Profile People born specifically on the 13th of December are predicted to be rather decisive and alert with excellent communication skills and the typical Sagittarian helpful optimism.
December 13th Work and Finances Being predictively technology minded can often guide the job choices most preferable to a person born on the thirteenth of December. December 13th Personal Relationships For a Sagittarius, the person born on the thirteenth day of December is typically fun loving and romantic but also considerably private concerning affairs of the heart.
December 13th Health Illness is usually an uncommon event to a person born on December 13th as you have a tendency to be overly fussy regarding health matters. December 13th Strengths and Weaknesses Your main strengths of character are exposed within your attentive, thoughtful and insightful qualities along with your optimistic attitude and humorous resilience.click here
Zodiac Cusps in Astrology
December 13th Dreams and Goals Being born on the 13th of December means you may seemingly want it all yet you simply wish to achieve much with your talents and knowledge. December 13th Birthday Luck and Significance As you were born on the thirteenth day of the month the one and three in your birth date gain you a Root number of Four.
December 13th Horoscope Summation The influence of the celestial body Jupiter is believed to be astrologically responsible for the typified probabilities of all Sagittarius personalities. Horoscope Birthday Horoscope for next December Dates. Birthday Horoscope December 14th Birthday Horoscope December 14th, personal asctrological characteristic for those who were born on December 14th.
Birthday Horoscope December 15th Birthday Horoscope December 15th, personal asctrological characteristic for those who were born on December 15th. Birthday Horoscope December 16th Birthday Horoscope December 16th, personal asctrological characteristic for those who were born on December 16th. Birthday Horoscope December 17th Birthday Horoscope December 17th, personal asctrological characteristic for those who were born on December 17th.
Birthday Horoscope December 18th Birthday Horoscope December 18th, personal asctrological characteristic for those who were born on December 18th. Birthday Horoscope December 19th Birthday Horoscope December 19th, personal asctrological characteristic for those who were born on December 19th. Birthday Horoscope December 20th Birthday Horoscope December 20th, personal asctrological characteristic for those who were born on December 20th.
Birthday Horoscope December 21st Birthday Horoscope December 21st, personal asctrological characteristic for those who were born on December 21st. Comments: December Horoscope Sagittarius. Sarah I am a Capricorn daughter but my mom is born on December 13 and we can never get along. So people if you want to get married and are born in December, I'm saving you some heart ache don't marry a Capricorn, you will always be fighting and won't be happy.
The personality don't go together. December 13, Alex Turned 42 last month, it is me. I thought it was because I was a little spoiled growing up. Kimberly Me to a tee. Kimberly we share the same year as well. Im a proud Sagittarius. Ong Did not realise the day coming. Lui most of the content really speaking about who and what i am.
Love and Compatibility for December 13 Zodiac
Yuuka yeah definitlely true! Maryam My birthday mate. Exact date too. Manisha Pattnaik ditto Nickolas That is perfectly me. My last year birthday almost take my life. I try to understand the reason why i fall sick almost every year of my birthday than i find at that the old years die at of me so that the new one can come in.
Dr Kank It's freakishly true! How are you guys getting through life? Are some days really bad? And someday you feel extra good,if so how do you live with feeling insecure and unconfident sometimes,sometimes a relaxed state and sometimes just feeling overly confident ,sometimes overly emotional that I make things worse for myself?
Your sign is:
Any suggestions friends?? Lauren Scary how true this all is for me!! Cristina This is so me. Tia This is all of me! I kinda cried I'm still trying to find myself a single mom and trying to figure bout what I need to do in my life to grow I do want everything to happen now and I'm very impatient person I love hard and very loyal ughhh were is my confidence I think once I get out and start doing me I will get back to the person I use to be.
Me I was also born on this day in This is me to the letter!! I don't really care about having a girl friend anymore not trying to be pretentious because i don't think it will suit my purpose in life. I had to experience a lot of pain to actually to grow up.
I am an extremely late bloomer. I had a lot of karma to deal with. Zaq waaat, thats me. Nikolai Most of it was right except for the learning part. I only like learning what I'm interested in. Ryan Anyone else relate more to their conceived zodiac? J, Sal I was really impressed, it was a look into my own thoughts and ideas, expressed by someone who's never met me Nhat Just turned 22 yesterday.