Zodiac constellations are constellations that lie along the plane of the ecliptic. The ecliptic, or the apparent path of the Sun, is defined by the circular path of the Sun across the sky, as seen from Earth. In other words, the Sun appears to pass through these constellations over the course of a year. The passage of the Sun through the zodiac is a cycle that was used by ancient cultures to determine the time of year. Most of the planets in the solar system have orbits that take them near the ecliptic plane, within about 8 degrees. Taurus is a large constellation in the northern sky. Its name means "bull" in Latin. The constellation is symbolized by the bull's head, . It is one of the oldest constellations. Its history dates back to the Bronze Age.  

 

Taurus is one of the 12 constellations of the zodiac, first catalogued by the Greek astronomer Claudius Ptolemy in the 2nd century CE. In Greek mythology, the constellation is associated with Zeus, who transformed himself into a bull to get close to Europa and abduct her. Taurus is known for its bright stars Aldebaran, Elnath, and Alcyone, as well as for the variable star T Tauri. The constellation is also home to the Pleiades (Messier 45), also known as the Seven Sisters, and the Hyades, the two nearest open star clusters to Earth. The gravitational pulls of the Sun and Moon on the Earth are such that they are trying to tip the globe over with the end result of sending the Earth into the slow wobble called precession. Precession is the phenomenon which allows a person on a moving bicycle to lean towards one side and, instead of falling over, turning into the direction of the lean. Now the zodiac is the band of constellations or star pictures the Sun appears to move in front of during the year. A consequence of precession is that the zodiac constellation that the Sun is in front of any date shifts by approximately one constellation every 2000 years. Another change is that originally the zodiac was split into 12 star signs, but astronomers today recognize 13 constellations along the zodiac, with Ophiuchus being the 13th. A constellation is a group of stars that appears to form a pattern or picture like Orion the Great Hunter, Leo the Lion, or Taurus the Bull. Constellations are easily recognizable patterns that help people orient themselves using the night sky. There are 88 "official" constellations. 

 

Not necessarily. Each constellation is a collection of stars that are distributed in space in three dimensions - the stars are all different distances from Earth. The stars in a constellation appear to be in the same plane because we are viewing them from very, very, far away. Stars vary greatly in size, distance from Earth, and temperature. Dimmer stars may be smaller, farther away, or cooler than brighter stars. By the same token, the brightest stars are not necessarily the closest. Of the stars in Cygnus, the swan, the faintest star is the closest and the brightest star is the farthest! Most of the constellation names we know came from the ancient Middle Eastern, Greek, and Roman cultures. They identified clusters of stars as gods, goddesses, animals, and objects of their stories. It is important to understand that these were not the only cultures populating the night sky with characters important to their lives. Cultures all over the world and throughout time  Native American, Asian, and African have made pictures with those same stars. In some cases the constellations may have had ceremonial or religious significance. In other cases, the star groupings helped to mark the passage of time between planting and harvesting. There are 48 "ancient" constellations and they are the brightest groupings of stars - those observed easily by the unaided eye. There actually are 50 "ancient" constellations; astronomers divided one of the constellations (Argo) into 3 parts. "Modern" constellations  like the Peacock, Telescope, and Giraffe  were identified by later astronomers of the 1500s, 1600s, and 1700s who used telescopes and who were able to observe the night sky in the southern hemisphere. These scientists "connected" the dimmer stars between the ancient constellations. There are 38 modern constellations. In 1930 the International Astronomical Union officially listed 88 modern and ancient constellations (one of the ancient constellations was divided into 3 parts) and drew a boundary around each. The boundary edges meet, dividing the imaginary sphere the celestial sphere surrounding Earth into 88 pieces. Astronomers consider any star within a constellation boundary to be part of that constellation, even if it is not part of the actual picture. No, there are billions of stars, and only a fraction of them make up the shapes of our constellations these are the stars that are easily seen with the unaided eye. 

 

1. Have located the stars in the various constellation. The Sun is found at any time in the year.
2. Based on this the birth dates are determined for its meaning. But any year or every year the sun is found in the same place and same time.
3. The various constellation connected to sun and earth are Sagittarius, Capricorn, Taurus, Gemini, Cancer, Aquarius, Pisces, Virgo, Libra and Scorpio, Aries.
4. The constellation and date numbers are defined with appropriate meaning.
5. For example, the Sun is found to be in Virgo from September 16 to October 31.

 All stars, however, fall within the boundaries of one of the 88 constellation regions. As astronomers studied the night sky with modern telescopes, they were able to discern stars in the dark spaces around the constellations stars that were not part of the original star pictures. You can see some of these stars by observing the sky on a dark night. If you look at the sky with binoculars, you will see even more stars. If you have a telescope, you will see even more! All the stars you see belong to one special group of stars the stars in our own galaxy, the Milky Way. Hundreds of the brightest stars, those visible with the unaided eye, were given names in ancient times. These include Eltanin of Draco, the Dragon, and Vega in Lyra, the Lyre. Many of these stars have multiple names, having been observed by different cultures. Today stars are named by their coordinates on the celestial sphere. This is an imaginary sphere surrounding Earth. Earth's north and south poles can be extended in space to this sphere, marking the north and south celestial poles, the poles around which the sphere spins. Polaris marks the intersection of the extended north pole and the sphere. 

 

Earth's equator, extended into space, intersects the sphere at the celestial equator, dividing it into northern and southern hemispheres. All stars and objects in space, such as constellations, can be mapped relative to the poles and equator of the celestial sphere. Their position north or south of the celestial equator essentially their latitude is called "declination." Their position east or west essentially is their longitude, or right ascension, measured in hours, minutes, and seconds. On Earth, we measure our longitude east or west from Greenwich, England; right ascension on the celestial sphere is measured from the intersection of the ecliptic (plane of Earth's orbit) and the celestial equator. The stars are distant objects. Their distances vary, but they are all very far away. Excluding our Sun, the nearest star, Proxima Centauri, is more than 4 light years away. As Earth spins on its axis, we, as Earth-bound observers, spin past this background of distant stars. As Earth spins, the stars appear to move across our night sky from east to west, for the same reason that our Sun appears to "rise" in the east and "set" in the west. Stars close to the celestial poles, the imaginary points where Earth's north and south axes point in space, have a very small circle of spin. So if you find Polaris, Earth's north "pole star," you will observe it move very, very, very little in the night sky. The farther from Polaris, the wider the circle the stars trace. Stars that make a full circle around a celestial pole, like those in the Big and Little Dippers in the northern hemisphere, are called "circumpolar stars." They stay in the night sky and do not set. At the equator, there are no circumpolar stars because the celestial poles are located at the horizon. 

 

All stars observed at the equator rise in the east and set in the west. If observed through the year, the constellations shift gradually to the west. This is caused by Earth's orbit around our Sun. In the summer, viewers are looking in a different direction in space at night than they are during the winter. Earth orbits our Sun once each year. Viewed from Earth, our Sun appears to trace a circular path. This path defines a plane called the plane of the ecliptic (or just the ecliptic). The zodiac is the group (or "belt") of constellations that fall along the plane of the ecliptic. It is through these constellations that our Sun appears to "pass" during the year. While there are 12 astrological constellations of the zodiac, there are 13 astronomical zodiac constellations:  Capricornus, Aquarius, Pisces, Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Sagittarius, and Ophiuchus. The annual cycle of the zodiac was used by ancient cultures to determine the time of year. Most of the planets (except Pluto) also have orbits that are very close to the ecliptic plane defined by Earth's motion (within about 8 degrees above or below). If you include all the constellations encompassed by this broadened definition of the ecliptic plane, you have 21 to 24 constellations of the zodiac! The astrological signs were identified and connected to the calendar about 2500 years ago. However, since that time, the timing of Earth's seasons has shifted. This is partly due to the fact that Earth wobbles a little like a top, making its axis point in different directions at different times. This is a predictable cycle of change over a period of about 23,000 years. Because the direction of the Earth's axis of rotation determines at which point in the Earth's orbit the seasons will occur, this wobble will cause a particular season (for example, northern hemisphere winter) to occur at a slightly different place over time. Through time, then, the seasons have shifted with respect to the background of the zodiac constellations. Five thousand years ago, our Sun passed through Taurus during the spring equinox; today it is in Pisces at the start of spring. So if you ever wonder why your horoscope may be off a bit ... perhaps by several thousand years ... this shift may be the reason!

Step-by-step explanation

Only because we know the pattern of the sky generally this pattern never changes. So, for example, just after sunset people could see the constellation just above the western horizon and just before the next sunrise people could see the constellation just above the eastern horizon, so the sun had to be halfway between those two constellations. As you have realized, one can never see the actual constellation that the sun itself is currently in, because the sun washes it out.

Remember that the sun is no longer synchronized with the astrological signs: when astrologers say that the sun-sign is Aries, the sun is actually in Pisces. The sun is now always one constellation after the astrologers' named sign. The signs matched the constellations 2000 years ago when astrology was set up, but have now shifted. 

 

The zodiacal constellations are found in a ring along the celestial equator, formed from the chance superposition of the stars which lie along these lines of sight. As the Earth rotates once around the Sun in a year, the Sun appears to pass through (or lie in front of) each of these constellations in turn. Its path is called the ecliptic. Because the Earth is tilted by 23 degrees with respect to its orbital plane, the ecliptic moves up and down between +23 and -23 degrees of the celestial equator. On the spring and fall equinoxes (March 21 and September 21), the two coincide.

The peak altitude of the Sun each day, as viewed from the northern hemisphere, increases by 23 degrees from March 21 until June 21 (the summer solstice). On this day the Sun is said to stand still in the sky, and then it turns around and heads back toward the celestial equator, crossing it again on September 21 and then descending further in the sky every day till December 21 (the winter solstice). On the solstices, the Sun lies directly overhead at noon at the Tropics of Cancer or Capricorn (23 degrees above and below the equator).

If you like to read the daily astrological horoscopes in the newspapers for yourself and your friends and family, you are probably familiar with the names of these constellations: Gemini (the Twins), Cancer (the Crab), Leo (the Lion), Virgo (the Maiden), Libra (the Scale), Scorpio (the Scorpion), Sagittarius (the Archer), Capricorn (the Goat), Aquarius (the Water-Carrier), Pisces (the Fish), Aries (the Ram), and Taurus (the Bull).

 

A constellation which is overhead at midnight during a particular month will then lie behind the Sun six months later, because of the Earth's yearly motion around the Sun.

One might expect the birth dates associated with each constellation to match the dates on which the Sun lies within that constellation. A quick check, however, shows that Aquarius (the astrological sign for those born between January 20 and February 18) lies behind the Sun in early March, not February, and that the other dates are off as well. This mismatch occurs because over time the precession of the equinoxes, due to a wobble in the orientation of the Earth's rotational axis, has shifted the timing between the seasons and the constellations. As the Earth's rotational axis shifts slightly, it can take a few minutes extra for spring, and each of the other seasons, to arrive, because they depend on the Earth pointing exactly toward, away, or perpendicular to the direction to the Sun. Over thousands of years those few minutes can add up, leading to delays of weeks or even months. The same factor will slowly shift our rotational axis toward and away from Polaris over time, leading to new contenders for the title of North Star.