Based on some 20th century developments in astronomical science, astrologers in the 1970s identified a potential 13th zodiac sign known as Ophiuchus, which would align with the sun from December 1 through the 18th. This information is based on a constellation called Ophiuchus, which has been identified since ancient history and has been documented in relatively recent history, including the 18th century. Ophiuchus, which translates from Greek as "serpent bearer," is an image of a man grappling with a large snake.
Though multiple proposals from multiple astrologers suggested incorporating Ophiuchus into the traditional 12-sign zodiac, this effort has not been met with mainstream success. Ophiuchus may be most popular among some Japanese astrologers, who seem to have been open to incorporating this sign. Though the use of Ophiuchus as a 13th sign has not been met with mainstream success, ancient astrology texts dating back to 10 C.E. makes mention of this constellation as an astrologically significant presence. As the serpent bearer, Ophiuchus may be associated with snakes and poisons, typically in a protective capacity. This protective capacity may further associate Ophiuchus with those who provide medical care, including doctors. Astronomers have been known to make reference to Ophiuchus as the 13th zodiac sign, but because those professionals tend to discredit astrology, their authority on this matter is questionable.