DON'T GO THERE!!!!!!!!!!!!!!!!!!!
We've had enough debate on that a year or so ago. It is a constellation NOT a sign. Indeed it is not and never has been a signThere are only 12 Signs and always have been that's it LOL
Conversely signs are NOT constellations, the two are quite different, even though they share some of the same names.
Ophiuchus was never, ever considered important for Astrology. Only Astronomers seem to think that it should be used in Astrology.
Constellations are groupings of real stars in real space. They're all over the place LOL. Signs did originate out of a small group of constellations that lie on the ecliptic and whilst there are more than 12 constellations that project into the ecliptic only 12 were ever used for charting the ecliptic and only 12 became signs, as the system of measurement was codified,
If you look at the constellations you'll find they overlap and that some are bigger than others. Astrology (and Astronomy) used them as the basis for measuring planetary movements but tidied them up into the signs - 12 equal divisions of the ecliptic circle.
Oh, and it's nothing to do with the sidereal zodiac. That to has 12 equal signs, that do not match the actual constellations in terms of positionaThough the origin of that zodiac is measured from a star in Aries.
Now if you want to be kind to my blood pressure, you'll drop the issue entirely LOL
PS If you really want to know then here's the link to the relevant thread
http://www.tarotforum.net/showthread.php?t=54777&highlight=Constellations