Ophiuchus is the name of a constellation. It used to be called Serpentarius, the snake-bearer. It is closely interlinked with the constellation of Serpens, the snake (which the snake-bearer is carrying on his shoulder).
Within the constellation we find Poniatovski's bull: five stars that create a V. (Interesting piece of trivia: the TV series "Roswell" was about a war between the inhabitants of these 5 star systems).

Two stars in Poniatovski's Bull are important: 

Because of the "wobble" in the movement of both stars, astronomers believe that both have planets.

According to DeAnna Emerson, 70 Ophiuchi, which she calls Inanna, is the star system from which the original "snake-people" came that created man-kind through genetic engineering. She analysed Sitchin's material, came to the conclusion that the Sumerians were not the first "civilisation", but that they were preceded by the Ubadians, a Mother-Goddess worshipping civilisation. Apart from Nibiru, there would have been another "Planet X" which would be the real home of the original creators of Mankind.

Deanna Emerson also claims that originally, in the days of the Mother-Goddess worshipping cultures, astrologers (who in those days also were astronomers) worked with 13 Signs in the Zodiac. Ophiuchus, the snake-bearer, was that 13th Sign.