Originally Posted by
http://en.wikipedia.org/wiki/Ophiuchus
In the 2nd century, Ptolemy listed 29 stars in Ophiuchus. He recognized that most of those stars were north of the ecliptic (the path of the Sun through the sky) — however, 4 of them (today known as 36 Oph, 42 θ Oph, 44 Oph and 51 Oph) he recognized as being south of the ecliptic. Therefore, the Sun passed through the constellation of Ophiuchus as it was recognised by Ptolemy.
The reason that Ophiuchus is not a part of the western astrological zodiac is because that zodiac is defined on the basis of the sun spending an equal amount of time in twelve astrological signs starting at the vernal equinox in the northern hemisphere — this is called the tropical zodiac. There is also a sidereal zodiac, which is based on the actual location of the stars in the sky, and which is used by Hindu and some Western astrologers. At present, the sun is in Ophiuchus from November 30 to December 17.
Bookmarks