Zodiac in astrology

Astrologers use astronomical observations of the movements of the night sky for divinatory purposes. The zodiac remains in use in modern astrology, though the issue of tropical astrology (used mainly by Western astrologers) and sidereal astrology (used mainly by Indian astrologers) is central. At issue in the debate is whether the signs should be defined in terms of zones derived from nodal points defined by Earth’s motion during a tropical year , or whether the signs should be defined in terms of signs roughly aligned with the constellations of the same name (for sidereal astrologers). This matters because of an astronomical phenomenon called the precession of the equinoxes, whereby the position of the stars in sky has changed over time. Therefore, over the centuries the twelve zodiacal signs in Western astrology no longer correspond to the same part of the sky as their original constellations, or their Indian counterparts. In effect, in Western astrology the link between sign and constellation has been broken, whereas in Indian astrology it remains of paramount importance.