Ophiuchus is a constellation located around the celestial equator. It is not considered a zodiac sign because the zodiac signs are based on the positions of the Sun, not the stars, and its ecliptic path does not intersect the ecliptic, which is the path that the Sun follows in the sky over a year.

Astrology, which assigns personality traits and fortune based on the positions of the stars and planets, often follows a different system than astronomy, which is the scientific study of the celestial objects. In ancient times, astronomers recognized this constellation and divided the ecliptic into 12 equal parts, based on the constellations that the Sun traversed during the year. These 12 divisions, known as the zodiac signs, have cultural significance and are used in astrology.

Although Ophiuchus is visible in the night sky and even crosses the ecliptic at two points, it was not included as a zodiac sign because it does not directly align with the Sun's path. Therefore, astrologically speaking, the zodiac signs remain defined by the traditional twelve divisions of the ecliptic, even though the actual constellations might have slightly shifted over time due to the tilt of Earth's axis known as axial precession.