Ecliptic，astronomyThe term refers to the way the sun "walks" a year from the earth, which is caused by the earth's revolution around the sun.
People look at the sun from the moving platform of the earth. The sun rotates around the earth relatively - the sun moves slowly on the background of the sky, and moves exactly once a year to return to its original position. The sun "goes" the way (i.eEarth revolutionTrack oncelestial sphere) is called the ecliptic.[1]It is a big circle assumed by the celestial sphere, namelyEarth orbitProjection on the celestial sphere.It intersects the equatorial planeVernal equinoxandAutumnal equinox。
becauseEarth rotation axisNot perpendicular to the revolution plane, soCelestial equatorThe plane does not coincide with the ecliptic plane, and the two planes have an included angle of 23 ° 26'21 (measured in 2000 AD).Intersection of two planesCornerJust stay in jailVernal equinoxTake the autumn equinox.Looking across the earth,Northern HemisphereThe sun moves from south to north, which is called the winter solstice.Count one circle eastward from this field, 0 ° to 360 °, which is the longitude of the ecliptic (written as λ), and the angle is calledYellow meridianSeveral degrees.The latitude of the ecliptic is 90 degrees north and south, plus and minus.The orbit of the moon around the earth (i.e“Bai Dao”）And the orbits of the planets around the sun are very close to the ecliptic.
Chinese name
Ecliptic
Foreign name
ecliptic
Meaning
RevolutionTrack planeThe big circle intersected with the celestial sphere
Features
The instantaneous orbital plane always passes through the sun center
The ecliptic, taking the earth as the first angle of view, connects the earth and the sun into a line, becauseThe earth revolves around the sunAfter one year, the path of this line will form a plane, called the "ecliptic".[2]People on the earth look at the apparent path the sun takes between stars within a year, that is, the great circle where the earth's orbital plane intersects the celestial sphere.Ecliptic andCelestial equatorAt an angle of 23 degrees and 26 minutes, intersecting atVernal equinoxandAutumnal equinox。The ecliptic isAnnual apparent motion of the sunTrajectory, generally speaking, because people on the earth usually do not feel the movement of the earth (revolution), just as people sitting in a moving vehicle feel the backward movement of surrounding objects, what people on the earth see is that the sun moves backward on the starry sky background composed of stars, rotating once a year, which is called the annual apparent movement of the sun,The path of the sun (that is, the reflection of the earth's orbit on the celestial sphere) is called the ecliptic.
In the universe, the earth acts assolar systemOne of the planets in is constantly moving. Its movement is complex, but the most basic movement is the rotation and revolution of the earth.earth rotationIt's the earth itselfAutorotation shaftRotate from west to east.The earth's axis of rotation is called Earth's axis for short.The earth's axis is assumed, but when the earth rotates, it seems thatRoot axisThe exists of.The plane perpendicular to the earth axis through the earth center is calledEquatorial planeThe great circle that cuts the earth's surface is called the equator.The equator bisects the earthsouthern hemisphereAndNorthern Hemisphere。The earth's axis crosses the earth's center and the earth's surface at two points. The intersection in the northern hemisphere is called the North Pole, and the intersection in the southern hemisphere is called the South Pole.While the earth rotates on its axis, it also revolves around the sun from west to east.The orbit of the earth's revolution is an ellipse close to a perfect circle.The plane formed by this ellipse is called the orbital plane, also called the ecliptic plane.
In the solar system, the earth's orbital plane is the ecliptic, so the earth'saxial tilt It is especially called the angle of intersection of yellow and red.As the earth rotates on its axis, it revolves around the sun.In this process, the earth axis is not perpendicular to the orbital plane (ecliptic plane) of the revolution, but inclined, with an included angle of 66 ° 34 '.However, the tilt direction of the earth axis remains unchanged in space (translation), resulting in the equatorial plane not parallel to the ecliptic plane, but inclined, with an included angle of 66 ° 34 ′Cosine angleThat is 23 ° 26 '.This included angle is called the yellow and red angle.The tilt of the earth's axis and the direction of tilt remain unchanged, which also leads to the different tendencies of the earth's axis towards the sunSubsolar point From 23 ° 26 'north latitude toSouth LatitudeMove back and forth between 23 ° 26 '.The moving cycle is one year.This has resulted inNoon sun heightAnd the length of day and night, thus forming the four seasons.
Ecliptic
To put it simply, the earth revolves around the sun once a year. We look at the earth as the sun moves 365 or 366 times a year in the sky. The path of the sun's movement is called the ecliptic - it iscelestial sphereA large circle assumed on theEarth orbitProjection on the celestial sphere.The ecliptic and equatorial planes intersect at the vernal equinox and autumnal equinox.
In view of the complexity of motion changes, the strict definition of the ecliptic is also needed in some astronomical work: at any moment, the orbital plane that only considers long-term motion is called the instantaneous average orbital plane, and the great circle that this plane intersects with the celestial sphere is called the ecliptic.Seen from the center of the earth, the ecliptic is very close to the apparent anniversary path of the sun in the stars.Only applied precisionAstronomical instrumentTo detect the difference between the ecliptic and the apparent annual path of the sun.The ecliptic is on the celestial sphereEcliptic coordinate systemBase ring of.
Causes
The zodiac constellations are arranged along the eclipticCelestial equatorIt has an angle of 23 degrees and 26 minutes（Yellow declination angle）。The two intersections of the ecliptic and the celestial equator areVernal equinoxandAutumnal equinox, the ecliptic andTropic of Cancer、the Tropic of CancerThe intersection point of is the winter solstice and the summer solstice.The four seasons are formed because the earth revolves around the sun.Due to the existence of the ecliptic angle, the direct sunlight point moves back and forth between 23 ° 26 'north and south latitudes of the earthAnnual changeThus causing seasonal changes in the noon sun height and the length of day and night, resulting in seasonal changes in the amount of solar energy obtained by various regions, thus forming the replacement of the four seasons.
In the ecliptic coordinate system, the longitude of the celestial body is measured from the vernal equinox to the east along the eclipticYellow latitudeIs positive, and the south yellow latitude is negative.South and North YellowPolar distanceThe corresponding celestial poles are 23 degrees and 26 minutes.Due to the earth's revolutionMoonAnd other planetary perturbations,Earth revolutionThe orbit is not a strict plane, that is, it produces irregular continuous changes in space, including many short periods and a slow long-term movement.Short period motion can be eliminated by averaging in a certain period, eliminating theTrack planeIt is called instantaneous average orbital plane.
The strict definition of the ecliptic is:Earth moon systemThe great circle where the instantaneous mean orbital plane of the center of mass revolves around the sun intersects the celestial sphere.The ecliptic is the base circle of the celestial ecliptic coordinate system.
Ecliptic
The ecliptic is the apparent path of the sun on the celestial sphere during the year. It seems that the path of the sun moving among stars is also the path of the planets every year.More specifically, it is the intersection of a spherical surface (the celestial sphere) and the plane of the ecliptic;withgeometryIt is the average orbital plane containing the earth's orbit around the sun.The plane of the ecliptic should be the stable plane of the ecliptic, which is perpendicular to the orbital plane of all planetsangular momentumAnd, andJupiterIt should be the most importantInfluencer。The plane of the ecliptic inclines about 1.5 ° to the unchanging ecliptic.In fact, it can be simply understood as the plane where the earth revolves, and the 12 constellations above are called the ecliptic12 constellations, which is more vivid to understand.
The word "ecliptic" in the west extends from the place where eclipse takes place.
Solar“Visual movement”There are two situations, namely“Diurnal visual movement”And the "Anniversary Vision Campaign"."Sunday Apparent Movement" refers to the phenomenon that the sun rises in the east and sets in the west every day, which is essentially due toearth rotationA visual effect caused by;"Annual apparent motion" refers to the phenomenon that the sun "travels" between constellations caused by the earth's revolution.
Ecliptic
Astronomy refers to the annual apparent motion track of the sun on the earth, that is, the great circle of the apparent path of the sun in the sky, as the "ecliptic", that is, the revolution of the earthTrack surfaceProjection on the celestial sphere.The sun rotates once a year along the ecliptic on the earth. For the convenience of determining the location, people divide the ecliptic into twelve equal parts (each equal to 30 °), each named after a nearby constellation, which is called the zodiac constellation orZodiac。In this way, it is equivalent to dividing a year into twelve sections, in which the sun enters a constellation.
The earliest existing historical and written records of the ecliptic appeared in the Babylonian culture. They used the sun's position on the ecliptic to identify the dateTwelve constellationsThe earliest function is like the twelve months in the modern calendar,AriesStarting at the vernal equinox is considered the beginning of the year, and the day when the sun moves to Libra is the equinox.
zodiac
Around the 5th century BC,Babylon, CubaAstronomers first used“zodiac”This concept.Think of the whole sky as a big ball, and the stars are distributed inspherical shellGo ahead, this is what we callcelestial sphere。The ecliptic is the path of the sun on the celestial sphere.[1]
The area of 8 degrees on both sides of the ecliptic is the ecliptic zone.The planets move in the zodiac.The Babylonians also divided the zodiac into twelve regions, but the names of these regions came fromancient GreekPeople.In fact, most constellations are named afterMYTHOS。
Ecliptic surface
Ecliptic surfaceIt is the plane of the earth's orbit.Because the gravity of the moon and other planets and other celestial bodies affects the earth's revolution, the position of the ecliptic in space is always changing irregularly and continuously.But during the change, the plane always passes through the center of the sun at any time.The great circle where the ecliptic plane intersects the celestial sphere is called the ecliptic.
Yellow red relation
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Because of the earth'sAutorotation shaftIt is not perpendicular to the orbital plane, so the equatorial plane is not parallel to the ecliptic, but has an angle of 23 ° 26 ', which is known as the ecliptic angle.The great circles formed by the intersection of the equatorial plane and the ecliptic plane with the earth are called the equator and the ecliptic respectivelyEquinox(vernal equinox and autumnal equinox).The equinox when the sun passes from south to north is called the vernal equinox orAriesThe first point, the longitude of the ecliptic, is usually marked by the letter λ, starting at this point and moving eastward from 0 ° to 360 °.
The latitude of the ecliptic is usually marked by the letter β. The basic plane measured by the ecliptic is from 0 ° to 90 ° to the north and from 0 ° to - 90 ° to the south.The vernal equinox is also defined asEquatorial coordinateThe right ascension is also measured from 0 to 24 to the east, usually with the letter α or RA. Representation;DeclinationExpressed by the letter δ or Del., from the equatorial plane to the north, from 0 ° to 90 °, and to the south, from 0 ° to - 90 °.The simple rotation pattern can make α, δ and to λ, β convert each other.
Celestial body position
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1. Analysis of Ancient Chinese Scholars
Ecliptic
Among the existing literary works·Sima BiaoThe book of the Later Han Dynasty, Zhi, Lulizhong, Jia Kui Lun Li, analyzes the difference between the equator and the ecliptic in determining the position of celestial bodies, "Fu An and other officials used the ecliptic to measure how close the sun and moon are,Historiographer1Equatorial degreeIt is not the same as the sun and the moon. Today, when we look at the horizon, we are more than one day away from each other. We often play to think that we will change, but when we think of the sun, we retreat.In the ecliptic, you can walk freely without changing《Pentacene》On 'The sun and the moon follow the Yellow Path, reaching to Morning Glory in the south, and Dongjing in the north, and travel once a day, and seven of thirteen degrees and nineteen minutes a month'.Today's historiographer takes the equator as the degree, not the same as the sun and the moon. His fights, morning glory, (Dongjing), and Yu ghosts get 15 degrees at the equator, and 13 and a half degrees at the eclipticThe art of the sun and the moon follows the zodiac every day, and the moon follows the nine paths.withEquatorialThe winter solstice is 115 degrees away from the pole.The equator is in Dou 21, and the ecliptic is in Dou 19.LiangyiCoherence, the sun and the moon, the curve is poor, to advance and retreat.Therefore, the monthly line of well and cattle is more than 14 degrees, and it is more than 12 degrees in the corner and Lou.None of them can respond quickly. "That is to say, as far as the moon is concerned, the "chord" date andrunning speed It is different.The same is true of other celestial bodies.
2. Analysis of Western Scholars
Equatorial coordinate systemIt has no direct relationship with the ecliptic coordinate system, "as de Saussure (1740-1799) said:GreeceAstronomy is' ecliptic, angle, truth, anniversary '";Chinese astronomy is' equator, time, average, Sunday '.According to someArched polar starTo determine the equatorialMarkers, systematically observing theMidheavenThe Chinese have never lost their constellations, which change from time to time, so they can determine the position of the sun and the moon when they are invisible. "Gongji star refers toConstant display ringandConstant hidden circleThe inner star.The stars in the constant display circle are alwaysHorizon circleTherefore, the sum of their upper midheaven andLower Midheaven。The stars in the hidden circle are always below the horizon and never rise, so they are invisible.
See the Constant Display Circle Chart: that is to say, the equatorial coordinate system is based on the circle inside the constant display circlePolarisTo determine the time.An important feature of this system different from western astronomy is: "It isCelestial pole, equatorial, not planetary, ecliptic. "The ecliptic coordinate system isSunriseThe ecliptic eclipse is to observe the appearance and disappearance of stars near the ecliptic before sunrise or after sunset.We all rememberAncient EgyptWell known rightSiriusThe observation of the heliocentric days.Such observation does not require knowledge of the celestial pole, meridian or equator, nor does it require anyChronometrySystem, which naturally leads people to become familiar with the constellations of the ecliptic and the sum ofZodiacStars haunting at the same time... "
The equator and the ecliptic are like cars running on two tracks. They don't go the same way.The constellations of the equator and the zodiac are likeexpresswayIt is different from the stops and exits of ordinary roads.We cannot go to the expressway to find the stops and exits of ordinary roads, nor can we go to ordinary roads to find the stops and exits of expressway.Similarly, you can't goEquatorial coordinate systemOftwelve nocturnal time divisionsFind inZodiacNeither can we go to the zodiac coordinate system to find the objective basis of the twelve stars.
Other related
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Zodiac
The word zodiac comes fromGreekzodiakos。Astronomically, the orbit of the sun around the earth with the earth as the center is called the "ecliptic".The ecliptic is 18 degrees wide and 360 degrees around the sun,Ecliptic surfaceIt includes the orbits of all planets, as well as constellations. There is one constellation within the range of about every 30 degrees, totaling twelve constellations, called“Zodiac”。The earth moves from west to east on the ecliptic, circling the sky once a year.There are twelve constellations on a belt on both sides of the ecliptic. They areAries、Taurus、Gemini、Cancer、leo、Virgo、libra、scorpio、sagittarius、Capricornus、aquariusandPisces。People on the earth can see them successively within a year.
Babylon, CubaPeople have made long-term observations of these constellations, determined the ecliptic through observation, and divided the ecliptic into 12 equal parts, 30 degrees each, called 1 segment.The earth moves around the ecliptic for one time in 12 months, so it moves on the ecliptic for one time every month.In the eyes of the ancients, the sun wasApolloGod, the place where it rests must be a magnificent palace, so they called the first section of the zodiac the first palace.In this way, the 12 segments of the ecliptic will become“Zodiac”。The names of the 12 zodiac signs are similar to the 12 constellations near the ecliptic, namelyAries Palace, Taurus Palace, Double UterusCancer Palace、Lion Palace、Virgo Palace、Libra、Scorpio Palace、Renma Palace、Capricorn、aquariusandPisces Palace。
Ecliptic
althoughZodiacIts name is the same as that of the 12 constellations near the ecliptic, but they have essential differences.The twelve signs of the ecliptic indicate the position of the sun on the ecliptic, and the size of the houses is fixed.It is 30 degrees. The time when the sun enters each house is basically fixed. The sun comes around March 21 every yearVernal equinox, enter the Aries Palace;Come around June 22Solstice point, enter Cancer Palace;Arrive later before September 21Autumnal equinox, enter the libra palace;Come around December 22Winter solstice, enter Capricorn.When a person is on his birthday, the sun just passes his star house, so a person cannot see his own constellation on his birthday.
However, this was not the case 2000 years ago, because under the gravity of the sun and the moon,Earth rotation axisIn the sky, it does not point to the same position, but turns in circles in the sky.This phenomenon is calledprecession of the equinoxes。Due to the precession, the sun was in Aries, CancerLibraandCapricorn。AndZodiacDifferent, the 12 constellations near the zodiac are different in size, for example, Pisces is 49 degrees wide, while Cancer is only 21 degrees wide;The 12 constellations are not necessarily located on the ecliptic, but are located at 8 degrees on both sides of the ecliptic.
The zodiac passes through 13 of the 88 constellations. Because Westerners taboo the number 13, they think that snakes are the representatives of evil, soOphiuchusWas excluded from“Zodiac”In addition, the names of the zodiac constellations have changed many times, many of which are related to myths, most of which are named after animals.[1]zodiacIt was first symbolized by the twelve constellations of the zodiac,AverageIt is divided into 12 parts, called "the twelve zodiac palaces", which means "residence",the said day, the moon, and the planets will have a rest every time they go. The division of the "twelve zodiac signs" later cameancient Greek、ancient India、arabAs well as the whole of Europe, it was introduced to China in the Sui Dynasty.[1]
Zodiac
The earth is a nearly spherical celestial body. If you stand on the earth and look at the sky, the sky is also a sphere (short forcelestial sphere）The stars in the sky are like jewels embedded in this celestial sphere.[2]If people regard the vast universe as a celestial sphere, then the 88 constellations in the universe divide the entire celestial sphere into two parts: the north celestial sphere and the south celestial sphere.According to the fact that most of the areas of each constellation are in the northern sky or in the southern sky, they are calledNorthern constellationOr the southern constellation.According to this division, there are 28 constellations in the northern sky, 48 constellations in the southern sky, and 13 constellations in the zodiac.So what does the zodiac mean and what does the zodiac sign mean?The earth revolves around the sun once a year.Earth revolutionWhen looking at the sun from the earth, the sun moves slowly on the celestial sphere and among stars in the same direction as the earthDirection of revolutionThe same, that is, from west to east, is also the anniversary of the sun, which moves a large circle a yearVisual movement。
The zodiac signs are in common (in order): Aries, Taurus, Gemini, Cancer, LeoVirgo, Libra, Scorpio, OphiuchusSagittarius, CapricornAquariusPisces.
The zodiac passes through 13 of the 88 constellations. Except for a small part of Ophiuchus, the rest of the zodiac constellations are Pisces, Aries, Taurus, GeminiCancer, Leo, Virgo, Libra, ScorpioSagittarius, CapricornAquarius, collectively referred to as the twelve constellations of the ecliptic.
Zodiac
The names of the zodiac constellations have indeed undergone many changes, many of which are related to myths, most of which are named after animals.Nine planetsIn addition to Pluto,Rail inclinationThe biggest isMercuryThe orbital inclination of other planets is generally between 1 ° and 3 °, while Pluto is more than 17 °.This shows that, except Pluto, no matter where it moves, all the other planets will always be located in the sky on either side of the ecliptic, often in this or that eclipticIn the constellationAppear or pass, never go to other constellations.The sky area with 8 ° on both sides of the ecliptic and a total of 16 ° wide is called the zodiac belt, also called the beast belt.
The ecliptic is the sun, moon, planet, etcCelestial appearanceThe place where they pass through the sky is the corridor.In addition to this characteristic, the size of the zodiac constellation is also different.The largest zodiac constellation is Virgo, which occupies an area of 1294 square degrees on the celestial sphere, more than 1/32 of the total celestial sphere area of 41253 square degrees.Leo is also a relatively large constellation of the zodiac, with an area of about 947 square degrees.The last two zodiac constellations are Aries and Capricorn, 441 and 414 square degrees respectively.The area of the smallest zodiac constellation is less than 1/3 of the largest.
EclipticRepresentationSimilar to the Earth's equator, the Earth's equator is in the east-west direction of Britaingreenwich observatory Is the starting point, which is represented by longitude division.From here to the east is the east longitude, from 0 ° east longitude to 180 ° east longitude;The westward direction is west longitude, from 0 ° west longitude to 180 ° west longitude;East and west longitude 180 ° overlap.The zodiac is used in east-west direction“Yellow meridian"From east to west is 0 ° to 360 °, and the intersection of the ecliptic and the celestial equator is specified--Vernal equinoxThe point is the starting point, and the yellow longitude is 0 °.The circle of the ecliptic circle of the celestial sphere is 360 °, but the 12 zodiacal constellations are not all generally long in the east-west direction.The longest isVirgo, 44 ° long on the ecliptic, almost 1/8 of the total length of the ecliptic;The shortest isCancer, only 20 °.
Note: The 13 constellations of the zodiac belong to astronomy, and the date is not used to predict character and fortune.
Astrological significance
stayBabylonian Age, on March 21 every yearVernal equinox(Spring Equinox) Just as the sun enters AriesStellar clusterThey are not fixed. They only move at a very slow speed. We call this movement Precession. At that time, there were only twelve constellations on the ecliptic.In modern times, because of the relationship between precession and axis movement, Ophiuchus berths in the eclipticVernal equinoxThe point has been moved toPisces。
Astrologers in Greek times have long found this problem, but for ancient astrologers, the vernal equinoxAriesThe starting point of is the important coordinate that defines the position of the planet. If it moves constantly, it will be difficult to determine the position of the planet. So the astrologers and astronomers in Greece and Rome decided to maintain the vernal equinox on March 21 every year,EquinoxSun positionAs the starting point of Aries on the zodiac, and called such a zodiac system the Tropical zodiac, however, astrologers in India insist that Aries in the skyStellar positionIt is the starting point of the ecliptic, and such ecliptic calculation method is called the sidereal zodiac.
Ecliptic
Astronomy has a more precise way to distinguish the ecliptic, which is why the laterThirteen constellationsandTwelve constellationsIn dispute, what people usually say about their zodiac sign isAstrologyThe one of.But you often ask others what constellation it is. In astrology, the correct saying is, which constellation of the zodiac was the sun in when you were born,Europe and AmericaAnd most astrologers you come across use the zodiac, but if you go to an Indian astrologer, he may use the stellar ecliptic.Ophiuchus has been listed as a regional coordinate on the ecliptic by "astronomers", and the time when the sun passes through each constellation is not fixed like returning to the ecliptic, andjyotish astrology The stellar ecliptic used is indeed closer to the astronomical ecliptic position.
In astrologyAstrolabeupperZodiacThe symbols of are as follows:
Chinese Name
Symbol
Aries
♈
Taurus
♉
Gemini
♊
Cancer
♋
leo
♌
Virgo
♍
libra
♎
scorpio
♏
Sagittarius
♐
Capricornus
♑
Aquarius
♒
Pisces
♓
Ecliptic
The ecliptic is 23 degrees and 26 minutes from the equatorAngle of intersection（Yellow declination angle）；Because the earth's revolution is perturbed by the direction of the moon and other planets, the earth's revolution orbit is not a strict plane, that is, it produces irregular continuous changes in space, which includes many short periods and a slow long-term movement.Short period motion can be eliminated by averaging in a certain period of timeperiodic motion The orbital plane of is called the instantaneous planar orbital plane.The strict definition of the ecliptic is: Earth MooncentroidInstantaneous average of revolution around the sunTrack plane?The great circle where the celestial sphere intersects.The ecliptic is the base circle of the zodiac on the celestial sphere.
