Constellation

A constellation, in astronomy, is a group of conventional stars whose position in the night sky seemed so close that astronomers of ancient civilizations linked by imaginary lines decided, devising and figures on the celestial sphere. In the vastness of space, however, the stars of a constellation are not necessarily associated, may be even hundreds of light years away from each other. Moreover, these groups are completely arbitrary, because different cultures have devised different constellations, including linking them stars. Even so, some groups tend to recur because of their peculiar configuration, as is the case of Scorpius, the scorpion, its apparent magnitude (brightness) of stars or due to the passage of some recurring celestial bodies-planets Luna and their by-inmediaciones.

Se constellations usually separated into two groups, depending on the celestial hemisphere where they are:

1. Northern constellations, located north of the celestial equator

2. Southern constellations in the south.

Due to the time elapsed and the lack of historical records, it is difficult to know the precise origin of the oldest constellations in the western world. It seems that Leo, the Lion, Taurus the bull, and Scorpius, the scorpion, there was a long time in the culture of Mesopotamia, some 4000 years before the Christian era, though not necessarily receiving those names. It is believed that the interest of these old towns in the arrangement of the stars was primarily practical reasons, usually with agricultural purposes, travel and religious aid for measuring time and seasons and to provide guidance to mariners and merchants when conducting overnight trips, either by sea or desert. Thus, imagining figures which relate to groups of stars (and creating legends and stories of what they represent, see Mythology, Astrology-) would be easier and safer routes to remind seguir.De 88 constellations adopted by the International Astronomical Union (UAI), almost half come from the imagination of the Greek astronomers. Orión Homer mentions in the Odyssey. In Ancient Egypt was known as Sahu thousand years earlier.

The Zodiac is divided into twelve constellations, born in Babylon during the reign of Nebuchadnezzar II century a. VI C., linked to the twelve year lunation. We adopt the Greek culture, giving the current name the constellations.

The most famous are the constellations of the zodiac which are in a banda which passes the sun and planets. These constellations were the following.

Aries the ram , Taurus the bull, Gemini the twins, Cancer the crab, Leo the lion, Sagittarius the archer, Capricorn the sea goat, Aquarius the water carrier or water carrier, Pisces the fish.

The constellations in this list are considered the oldest, having an obvious importance in astrology (discipline formerly confused with astronomy). It should be noted that this list of 12 constellations, it would add, modern, a thirteenth: Ophiuchus, the serpentarium. Currently, and astronomically speaking, the sun passes through its boundaries, as defined by the IAU from November 30 to December 17. The former probably did not take this into consideration (or not revealed) for aesthetic reasons or astrological, or simply to the time of the first creators of the Zodiac did not exist.